Compositions and methods for prophylaxis and / or treatment of amyloid b peptide proteinopenia in alzheimer's and other diseases

Abstract

Material compositions and / or methods useful for the prophylaxis and / or treatment of protein depletion (proteinopenia) are provided, including material compositions that retains native function of a peptide / protein while limiting and / or preventing amyloid formation and / or aggregation of said peptide / protein. Material compositions and formulations for enhancing peptide / protein solubility, stability, circulation time, receptor interaction, brain penetrance, CSF half-life, facilitating peptide / protein synthesis and purification are also provided.

Description

COMPOSITIONS AND METHODS FOR PROPHYLAXIS AND / OR TREATMENT OF AMYLOID B PEPTIDE PROTEINOPENIA IN ALZHEIMER’S AND OTHER DISEASESCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to, and the benefit of, U.S. Provisional Application No. 63 / 520,068 filed August 16, 2023. which is incorporated by reference in its entirety. This application is related to international patent application No. PCT / EP2022 / 064374 filed 26 May 2022, which claims priority to U.S. Provisional Application No. 63 / 193,258, filed on of 26 May 2021, which is incorporated by reference herein in their entirety7.TECHNICAL FIELDThe present disclosure pertains to compositions for preventing and / or treating aggregation of proteins in proteinopenia.SEQUENCE LISTING

[0002] This application contains a Sequence Listing which has been submitted electronically in XML format via EFS-Web and is hereby incorporated by reference in its entirety. Said XML copy, created on August 16, 2024, is named AD_PCT_SequenceListing_20240815 and is 2091 kilobytes in size.BACKGROUND

[0003] The amyloid P peptide A 42 is a 42-amino acid peptide that is evolutionarily conserved and expressed in the central nervous system (CNS). A 42 and other amyloid proteins derive from the sequential cleavage of amyloid precursor protein (APP) by P and y secretases. The physiological concentration of Ap42 in human CSF is in the picogram / ml range (800-1200 pg / ml). The levels of soluble AP42 in the CSF are below normal (proteinopenia) in Alzheimer’s disease (AD) and many other neurodegenerative diseases including frontotemporal dementia (FTD). amyotrophic Lateral Sclerosis (ALS), Parkinson’s disease (PD) Parkinson’s disease dementia (PDD), dementia with Lewy bodies (DLB), multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD). The depletion of the peptide in these diseases results either from sequestration of soluble monomer through aggregation and amyloid plaque formation, or from heritable mutations in familial forms of the disease, some of which also lead to increased aggregation. So far, most of the therapeutic approaches for AD and related neurodegenerative disorders have focused on removing the aggregated forms of Ap42 orfurther reducing the AP42 monomer in the CSF, both of which often lead to worsening of cognition. Other approaches are directed to interfere with aggregation process and prevent plaque accumulation, which can maintain the available levels of soluble Ap42 but does not actively restore the normal concentration of the peptide when sequestered in aggregates and depleted below normal levels.SUMMARY OF INVENTION

[0004] In one aspect, an Ap peptide analogue for the treatment or prevention of Ap proteinopenia includes an N-terminal domain corresponding to positions 1-18 of SEQ ID NO: 1; a middle domain corresponding to positions 19-24 of SEQ ID NO:1; and a C-terminal domain corresponding to positions 25-42 of SEQ ID NO:1 that includes a modification. The modification includes (a) deletion of 1-13 amino acids; or (b) at least one of: (i) a C- terminus modification to an amide, N-alkyl amide, cysteamide, ester, aldehyde, hydrazide or hydroxamic acid; and (ii) a C-terminal domain substitution that includes an amino acid, an amino acid analogue, or both. The N-terminal domain can have at least 85% identity to positions 1-18 of SEQ ID NO: 1, and the middle domain can have at least 85% identity to positions 19-24 of SEQ ID NO: 1. The Ap peptide analogue may also include where the C- terminus modification is one of an amide, N-alkyl amide, cysteamide, an ester, an aldehyde, a hydrazide, or hydroxamic acid.

[0005] The Ap peptide analogue may also include where the C-terminal domain substitution includes one or more prolines. The Ap peptide analogue may also include where the C-terminal domain substitution includes one or more charged amino acids. The Ap peptide analogue may also include where the C-terminal domain substitution includes one or more polar amino acids. The Ap peptide analogue may also include where the C- terminal domain substitution includes one or more amino acids selected from the group consisting of proline, glycine, lysine, arginine, histidine, glutamic acid, aspartic acid, serine, threonine, asparagine, glutamine and cysteine. The Ap peptide analogue may also include where the C-terminal domain substitution includes one or more amino acid analogues. The Ap peptide analogue may also include where the one or more ammo acid analogues are peptoid substituents. The Ap peptide analogue may also include where the one or more amino acid analogues are selected from carboxyglutamic acid, D-proline, N-methyl leucine, N-(4-aminobutyl) glycine, N-(2-carboxyethyl) glycine, N-hydroxy methionine, N-methyl methionine, octenyl alanine and pyroglutamic acid.

[0006] The Ap peptide analogue may also include where the Ap peptide analogue includes an increased half-life in cerebrospinal fluid (CSF) relative to wild type Ap42 peptide. TheAp peptide analogue may also include where the A peptide analogue includes an increased protease resistance relative to wild type Ap42 peptide. The Ap peptide analogue may also include where the Ap peptide analogue has a decreased propensity for beta-sheet stacking and amyloid formation relative to wild type Ap42 peptide. The Ap peptide analogue may also include where the Ap peptide analogue includes increased solubility in a liquid medium relative to wild type AP42 peptide. The Ap peptide analogue may also include where the Ap peptide analogue performs a function of wild type Ap42 peptide to at least 50% of the level performed by wild ty pe Ap42 peptide. The Ap peptide analogue may also include where the function includes inducing a7 nicotinic acetylcholine receptor (a7nAChR) mediated Ca2+influx.

[0007] The Ap peptide analogue may also include where the Ap peptide analogue is selected from the group consisting of SEQ ID NOS: 190-1660. The Ap peptide analogue may also include includes (N-(4-aminobutyl)glycine) at position 34, position 35, or both. The Ap peptide analogue may also include includes (N-(2-carboxyethyl)glycine) at position 34, position 35, or both. The Ap peptide analogue may also include where the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:300, 514, 720, 926, 1132, 1338 and 1544. The Ap peptide analogue may also include where the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:402, 616, 822, 1028, 1234, 1440 and 1646. The Ap peptide analogue may also include where the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:301, 515, 721, 927, 1133, 1339 and 1545. The Ap peptide analogue may also include where the Ap peptide analogue is selected from the group consisting of SEQ ID NOS: 302, 516, 722, 928, 1134, 1340 and 1546. The Ap peptide analogue may also include where the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:303, 517, 723, 929, 1135, 1341 and 1547. The Ap peptide analogue may also include where the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:304, 518, 724. 930, 1136. 1342 and 1548. The Ap peptide analogue may also include where the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:305, 519, 725, 931, 1137, 1343 and 1549. The Ap peptide analogue may also include where the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:306, 520, 726. 932, 1138. 1344 and 1550. The Ap peptide analogue may also include where the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:307, 521, 727, 933, 1139, 1345 and 1551. The Ap peptide analogue may also include where the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:308, 522, 728, 934, 1140. 1346 and 1552. The Ap peptide analogue may also include where the Ap peptide analogue is selected from the groupconsisting of SEQ ID NOS:309, 523, 729. 935, 1141. 1347 and 1553. The A0 peptide analogue may also include where the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:310, 524, 730, 936, 1142, 1348 and 1554. The A peptide analogue may also include where the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:311, 525, 731. 937, 1143. 1349 and 1555. The Ap peptide analogue may also include where the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:400, 614, 820, 1026, 1232, 1438 and 1644. The Ap peptide analogue may also include where the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:203, 417, 623, 829, 1035. 1241, 1447 and 1649. The Ap peptide analogue may also include where the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:204, 418, 624, 830, 1034, 1242, 1448 and 1650.

[0008] In an aspect, a composition for treating or preventing Ap proteinopenia includes a therapeutically effective amount of the Ap peptide analogue of any one of claims 1 to 48 or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable vehicle.

[0009] In an aspect, a method of treating or preventing Ap proteinopenia in a subject includes administering to the subject a therapeutically effective amount of the Ap peptide analogue may also include. The method may also include where the therapeutically effective amount is sufficient to provide a concentration of the analogue in the CSF of a subject of about 200 to about 600 pg / mL. The method may also include where the therapeutically effective amount is lower than that for wild type AP42 peptide. The method may also include includes a prior step of identifying the subject as a candidate for treatment by determining a concentration of Ap42 in the CSF of the subject.

[0010] In an aspect, a nucleic acid encoding SEQ ID NO: 190 and a nucleic acid encoding SEQ ID NO:200 is provided. In one aspect, a method of treating or preventing Ap proteinopenia in a subject includes administering to the subject one or both of a nucleic acid encoding SEQ ID NO: 190 and a nucleic acid encoding SEQ ID NO:200.

[0011] Other technical features may be readily apparent to one skilled in the art from the following figures, descriptions, and claims.TERMS AND DEFINITIONS

[0012] Throughout this specification, including the claims which follow, unless the context requires otherwise, the word “comprise,'’ and variations such as “comprises” and “comprising.” will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. By “consisting of’ is meant including, and limited to, whatever follows the phrase"‘consisting of’ Thus, the phrase “consisting of’ indicates that the listed elements are required or mandatory, and that no other elements may be present. By “consisting essentially of’ is meant including any elements listed after the phrase, and limited to other elements that do not interfere with or contribute to the activity or action specified in the disclosure for the listed elements. Thus, the phrase “consisting essentially of’ indicates that the listed elements are required or mandatory, but that no other elements are present that materially affect the activity or action of the listed elements.

[0013] It must be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a pharmaceutical carrier” includes mixtures of two or more such carriers, and the like.

[0014] The use of the alternative (e.g., “or”) should be understood to mean either one, both, or any combination thereof of the alternatives. The term “and / or” should be understood to mean either one, or both of the alternatives.

[0015] As used herein, the term “about” or “approximately” refers to a quantity, level, value, number, frequency, percentage, dimension, size, amount, weight or length that varies by as much as 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2% or 1% to a reference quantity, level, value, number, frequency, percentage, dimension, size, amount, weight or length. In one embodiment, the term “about” or “approximately” refers a range of quantity, level, value, number, frequency, percentage, dimension, size, amount, weight or length ±15%, ±10%, ±9%, ±8%, ±7%, ±6%, ±5%, ±4%, ±3%, ±2%, or ±1% about a reference quantity7, level, value, number, frequency, percentage, dimension, size, amount, weight or length.

[0016] Reference throughout this specification to “one embodiment,” “an embodiment,” “a particular embodiment,” “a related embodiment,” “a certain embodiment,” “an additional embodiment,” or “a further embodiment” or combinations thereof means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the foregoing phrases in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. It is also understood that the positive recitation of a feature in one embodiment, serves as a basis for excluding the feature in a particular embodiment.

[0017] “Amino acid identity,” “residue identity,” “identity,” and the like, as used herein refers to the structure of the functional group (R group) on the polypeptide backbone at agiven position. Amino acid identities are (name / 3 -letter code / one-letter code): alanine / Al a / A; arginine / Arg / R; asparagine / Asn / N; aspartic acid / Asp / D; cysteine / Cys / C; glutamine / Gln / Q; glutamic acid / Glu / E; glycine / Gly / G; histidine / His / H; isoleucine / Ile / I; leucine / Leu / L; lysine / Lys / K; methionine / Met / M; phenylalanine / Phe / F; proline / Pro / P; pyrrolysine / Pyl / O; serine / Ser / S; threonine / Thr / T; tryptophan / Trp / W; tyrosine / Tyr / Y ; and valine / Val / V. Amino acids can be grouped according to similarities in the properties of their side chains. Such properties include size, charge, polarity, hydrophobicity, and chain rigidity / orientation. Accordingly, amino acids may be designated herein with reference to a property of their side chains e.g.. an amino acid having a hydrophobic, charged, or polar side chain may be referred to as a “hydrophobic amino acid”, "charged amino acid", or a “polar amino acid” respectively.

[0018] “Engineered” or “modified” as used herein to describe a peptide or nucleic acid refers to the aspect of having been manipulated by human intervention. Disclosed herein are engineered peptides, polypeptides, proteins, genes, etc. In one example, a protein is considered to be “engineered” when at least one aspect of the polypeptide, e.g., its sequence, has been intentionally manipulated by human intervention (directly or indirectly) to differ from the aspect as it exists in a patient / subject or in nature. Artificial manipulation may be accomplished by chemical synthesis or by the editing (insertion, deletion, mutation, etc.) of isolated segments of nucleic acids, e.g., by genetic engineering techniques. In contrast, “native” or “wild-type” as used herein refers to un-engineered and / or un-modified genes, peptides, proteins, nucleic acid sequences, amino acid sequences, and portions thereof.

[0019] An amino acid within a molecule may be substituted to create an engineered peptide or peptide analogue. The amino acid residue can be replaced by a residue having similar physiochemical characteristics, that is a 'conservative substitution’ - e.g., substituting one aliphatic residue for another or substitution of one polar residue for another. Alternatively, “non-conservative substitution” can entail replacing an amino acid residue with another residue having different or dissimilar physiochemical characteristics.

[0020] Similarity between amino acid or peptide sequences is expressed in terms of the homology of two sequences, otherwise referred to as sequence identity. Sequence identity is frequently measured in terms of percentage identity (percentage of identical residues for peptides or bases for nucleic acids; or similarity or homology); the higher the percentage, the more similar the two sequences are. Complete identity is 100% identical over a given sequence, for example 50, 100, 150, or 200 bases or residues.

[0021] ‘'Variant,’7as used herein refers to a polypeptide, gene, sequence, or molecule that is substantially homologous to a naturally occurring or reference member, but which is different from that of the native or reference member because of one or a plurality of deletions, insertions, substitutions, molecules, expression levels, etc.. Variant poly peptide- encoding DNA sequences encompass sequences that comprise one or more additions, deletions, or substitutions of nucleotides when compared to a native or reference DNA sequence, but that encode a variant protein or fragment thereof. A wide variety of cloning, PCR-based site-specific mutagenesis, and genomic editing approaches are known in the art, and can be applied by the ordinarily skilled artisan.

[0022] Variant amino acid or nucleic acid sequences can be at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%. at least 96%, at least 97%, at least 98%. at least 99%, or more, identical to a native or reference sequence. The degree of homology (percent identity) between a native and variant sequence can be determined, for example, by comparing the two sequences using freely available computer programs commonly employed for this purpose on the world wide web (e.g., BLASTp or BLASTn with default settings).

[0023] The terms “treat,” “treating,” and “treatment” refer to eliminating, reducing, suppressing, or ameliorating, either temporarily or permanently, either partially or completely, a clinical symptom, manifestation or progression of an event, disease or condition associated with proteinopenia and diseases described herein. As is recognized in the pertinent field, methods and compositions employed as therapies may reduce the severity of a given disease state but need not abolish every manifestation of the disease to be regarded as useful. Similarly, a prophylactically administered treatment need not be completely effective in preventing the onset of a condition to constitute a viable prophylactic method or agent. Simply reducing the impact of a disease and / or reducing the number or severity of associated symptoms, or by increasing the effectiveness of another treatment, or by producing another beneficial effect, or reducing the likelihood that the disease will occur or worsen in a subject, is sufficient.

[0024] “Therapeutically effective amount” means an amount of a drug, composition, compound, treatment, or therapy of the present disclosure that alone, or in combination with other therapies, (i) treats the particular disease, condition, or disorder, (ii) attenuates, ameliorates, or eliminates one or more symptoms of the particular disease, condition, or disorder, or (iii) prevents or delays, the onset of one or more symptoms of the particular disease, condition, or disorder described herein.

[0025] The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools, and methods which are meant to be exemplary and illustrative, not limiting in scope.BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIGS. 1A to 1LLL show exemplary peptide analogues having various modifications, particularly to the C-terminal end of the amyloid-beta protein.DETAILED DESCRIPTION

[0027] The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools, and methods which are meant to be exemplary' and illustrative, not limiting in scope.

[0028] This disclosure includes information that may be useful in understanding the present disclosure. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

[0029] A number of publications are cited herein in order to more fully describe and disclose the subject matter and the state of the art to which the subject matter pertains. Each of these references is incorporated herein by reference in its entirety into the present disclosure, to the same extent as if each individual reference was specifically and individually indicated to be incorporated by reference.

[0030] The present disclosure relates generally to proteinopenia conditions, and more specifically to methods, compositions and methods for the prophylaxis and / or treatment of amyloid [3 peptide proteinopenia in Alzheimer’s and other diseases.

[0031] A042 has potential neurotrophic effects and may play a role in synaptic plasticity and memory formation mainly via signaling through the a7 nicotinic acetyl choline receptors. It is hypothesized that the pathogenesis in AD and other neurodegenerative diseases where A042 is depleted below its normal physiological levels may be due to the loss of the important neuronal functions that require adequate concentrations of soluble monomeric A042. This understanding is in contrast with the prevailing view of A042- related pathogenesis, where instead of viewing toxicity as emanating directly from the aggregates / plaques (toxic gain-of-function), pathogenesis is seen as more dependent on the loss of the critical neuronal functions that require adequate levels of soluble A042 (toxicloss-of-function). Accordingly, instead of viewing AD and related diseases as analogous to cancer (i.e., a toxic mass), they can be viewed as analogous to diabetes mellitus (depletion of a crucial peptide), where replacement therapy has been very' successful. Therapeutic approaches to restore the normal concentration and function of Ap42 using non- aggregating / non-amyloid forming peptide analogues were previously described in prior patent application (PCT / EP2022 / 064374). By non-aggregating or non-amyloid forming, the mechanism of action to restore function is not the result of inhibiting propagation of P-sheet structure of the amyloid fibers, or otherwise to bind to or be incorporated into a P-sheet structure. Thus, in some variations, the Ap peptide may have a lower binding affinity’ or constant to wildtype or the analogues of Ap peptide, than to wildtype Ap peptide. The present disclosure provides new methods and compositions that further builds on the proteinopenia concept as the underlying pathogenic mechanism in AD and other neurodegenerative diseases where the Ap42 peptide is known to be depleted.

[0032] The wild-ty pe sequence of native AP42 peptide is as set forth in SEQ ID NO: 1. In accordance with the present disclosure, a non / low amyloid-forming peptide analogue of the AP42 peptide for correcting Ap42 depletion (proteinopenia) can comprise: a substantially intact AP42 N-terminal domain (positions 1-18), which is important for interaction with the a7 nicotinic acetyl choline receptor; a substantially intact AP42 middle domain (positions 19-24), which is mutated in familial forms of Alzheimer’s disease; and a C-terminal domain (positions 25-42), which in native Ap42 is responsible for amy loid formation, aggregation, and low solubility. As described herein, the analogue may include modifications to the C- terminal domain that decrease the analogue's propensity to form beta sheets. In various aspects, said modifications may impart other useful enhancements to the peptide analogue as compared to the native Ap42 peptide. Such enhancements include, but are not limited to, one or more of: increased solubility in a body fluid or other medium; increased stability e.g., in a body fluid or other medium; increased circulation time after administration to a subject; increased penetrance / uptake in the brain of a subject; increased half-life in CNS tissue and / or CSF; and decrease in the amount administered to a subject in order to achieve a given therapeutic effect. In some embodiments, these modifications may also facilitate synthesis and purification.

[0033] In some aspects, a non / low amyloid-forming peptide analogue of the Ap42 peptide can exhibit enhanced solubility in a body fluid and / or a pharmaceutically acceptable liquid medium, wherein the solubility is at least about 1 mg / ml. more preferably at least about 5 mg / ml and most preferably at least about 50 mg / ml. In various embodiments, the solubility in is at least about 1 mg / ml, at least about 2 mg / ml, at least about 3 mg / ml, at leastabout 4 mg / ml, at least about 5 mg / ml. at least about 6 mg / ml. at least about 7 mg / ml, at least about 8 mg / ml, at least about 9 mg / ml, at least about 10 mg / ml, at least about 1 1 mg / ml, at least about 12 mg / ml, at least about 13 mg / ml, at least about 14 mg / ml, at least about 15 mg / ml, at least about 16 mg / ml, at least about 17 mg / ml, at least about 18 mg / ml, at least about 19 mg / ml, at least about 20 mg / ml, at least about 25 mg / ml. at least about 30 mg / ml, at least about 35 mg / ml, at least about 40 mg / ml, at least about 45 mg / ml, or at least about 50 mg / ml.

[0034] In some aspects, a non / low amyloid-forming peptide analogue of the A(342 peptide can exhibit increased stability e.g. shelf life, wherein the peptide remains > 95% intact for at least about 2 years at about - 20 °C, more preferably remains > 95% intact for at least about 2 years at about 4 °C and most preferably, remains > 95% intact for at least about 2 years at room temperature.

[0035] In some aspects, a non / low amyloid-forming peptide analogue of the A(342 peptide can exhibit enhanced circulation time and half-life in CNS tissue and / or CSF, wherein the half-life in CSF is at least about 10 min, at least about 20 min, at least about 30 min, at least about 40 min, or at least about 50 min. More preferably the half-life is at least about 1 hours, at least about 2 hours, at least about 3 hours, at least about 4 hours, at least about 5 hours, at least about 6 hours, at least about 7 hours, at least about 8 hours, at least about 9 hours, or at least about 10 hours. Still more preferably the half-life is at least about 1 day, at least about 2 days, at least about 3 days, at least about 4 days, at least about 5 days, at least about 6 days, at least about 7 days, at least about 8 days, at least about 9 days, at least about 10 days, at least about 20 days, at least about 30 days, at least about 40 days, at least about 50 days, or at least about 60 days. Most preferably the half-life is at least about 10 weeks, at least about 20 weeks, at least about 30 weeks, at least about 40 weeks, or at least about 50 weeks.

[0036] In some aspects, a non / low amyloid-forming peptide analogue of the A(342 peptide can exhibit enhanced brain penetrance, wherein the percentage uptake in the brain as measured at no more than about 60 minutes after administration is at least about 0. 1 %, more preferably at least about 1% and most preferably at least about 10 %. In various embodiments, the percentage uptake in the brain as measured at no more than about 60 minutes after administration is at least about 0. 1 %. at least about 0.2 %, at least about 0.3 %, at least about 0.4 %. at least about 0.5 %, at least about 0.6 %, at least about 0.7 %. at least about 0.8 %, at least about 0.9 %, at least about 1.0 %, at least about 2 %, at least about 3 %, at least about 4 %, at least about 5 %, at least about 6 %, at least about 7 %, at least about 8 %, at least about 9 %. or at least about 10 %.

[0037] In some aspects, a non / low amyloid-forming peptide analogue of the A(342 peptide can exhibit enhanced receptor binding to the a7 nicotinic acetyl choline receptor (a7 nAChR), wherein the KD of binding to the a7 nAChR is about I pM or less, more preferably about 100 nM or less and most preferably about 10 pM or less. In various embodiments, the KD is about IpM or less, about 900 nM or less, about 800 nM or less, about 700 nM or less, about 600 nM or less, about 500 nM or less, about 400 nM or less, about 300 nM or less, about 200 nM or less, about 100 nM or less, about 1 nM or less, about 900 pM or less, about 800 pM or less, about 700 pM or less, about 600 pM or less, about 500 pM or less, about 400 pM or less, about 300 pM or less, about 200 pM or less, about 100 pM or less, about 90 pM or less, about 80 pM or less, about 70 pM or less, about 60 pM or less, about 50 pM or less, about 40 pM or less, about 30 pM or less, about 20 pM or less, or about 10 pM or less.

[0038] In some aspects, a non / low amyloid-forming peptide analogue of the A(342 peptide can exhibit enhanced synthesis yield and better urity, wherein the percent yield is at least 50% and percent purity is at least 90%, more preferably at least 95% and most preferably at least 98 %. In various embodiments, the yield is at least about 50%, at least about 60%, at least about 70%. at least about 80%, at least about 90%, at least about 92%, at least about 94%. at least about 96%, or at least about 98%, where in any of said embodiments, the purity is at least about 90%, at least about 92%, at least about 94%, at least about 96%, or at least about 98%.

[0039] As stated above, the non / low amyloid-forming peptide analogue of the A(342 peptide can comprise an N-terminal domain and middle domain that are substantially intact, i.e., exhibiting a high degree of identity to the corresponding domains of native A(342 peptide. Stated differently, any differences in the sequence of one of these domains in the analogue and that of the corresponding domain in native A(342 peptide do not decrease a native function mediated by that domain. In some embodiments, a non / low amyloid- forming peptide analogue of the A042 peptide can comprise an N-terminal domain having at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%. at least 97%, at least 98% or at least 99% identity to positions 1-18 of SEQ ID NO. 1. In some embodiments, a non / low amyloid-forming peptide analogue of the A(342 peptide can comprise a middle domain having at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% identity to of positions 19-24 of SEQ ID NO. 1. Accordingly, the analogue may exhibit enhancements such as described above while substantially retaining one or more of the native A(342 peptide's functions. For example, the analogue is able to perform the native function(s) at at least 50% of the level of the native soluble peptide (includinge.g. at least 55%, 60%, 65%, 70%. 75%. 80%, 85%, 86%, 87%, 88%, 89%. 90%. 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 1 0% of the level of the native soluble peptide). In particular aspects, the native function can comprise enhancing or inducing a7 nicotinic acetylcholine receptor (a7nAChR) mediated Ca2+influx.

[0040] In some embodiments such modifications may include deletion of one or more of the amino acids at positions 25-42, for example deletion of one to 13 amino acids. In certain embodiments, the deletion is consecutive and includes at least an alanine deletion at A[342 position 42. In some embodiments, such modifications may include a substitution of one or more of the amino acids at positions 25-42 (including any position therebetween, e.g. positions 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 or 42) with: an amino acid that interferes with beta-sheet formation such as P, G, K, R, H, E, D, S, T, N, Q, C; or an amino acid analogue that interferes with beta-sheet formation including e.g. 3- hydroxyproline, 4-hydroxyproline, selenocysteine, pyroglutamic acid, carboxyglutamic acid, octenyl alanine, pyrrolysine, palmitoyl aspartate, D-amino acids including D- proline, 0-amino acids, y-amino acids, homo-amino acids, -homo-amino acids, a-methyl amino acids, N-methyl amino acids, N-ethyl amino acids, N-alkylated amino acid derivatives (preferably with 1, 2 or 3 carbons in the alkyl moiety), peptoid substituents, pyruvic acid derivatives, branched-chain amino acid derivatives, nitro amino acid derivatives, halogenated amino acid derivatives, ring-substituted amino acid derivatives, aromatic amino acid derivatives, linear core amino acids, hydroxylated amino acid derivatives, cyclic amino acids, bicyclic amino acids. 3-amino-3-aryl-propionic acids, 3- amino-4-aryl-butyric acids, amino acids with aromatic spacers, alicyclic amino acids, a- phenylglycine derivatives, or the like.

[0041] In some embodiments, such modifications may include substitution of one or more peptoid substituents or derivatives thereof that interfere with beta-sheet formation. Examples of peptoid substituents include, but are not limited to, Nae (N-(2- aminoethyl)glycine), Nah (N-(2-aminohexyl)glycine), Nfur (N-(2-furfuryl)glycine), NGlu (N-(2-carboxyethyl)glycine), NHis (N-(methylimidazole)glycine). NLeu (N-substituted leucine). NLys (N-(4-aminobutyl)glycine), NLys(Me)3 (N-(4-(Ne, Ne,Ne- trimethylammonium)butyl)glycine), Nme (N-(2-methoxyethyl)glycine), NPhe (N- (phenylmethyl)glycine), Nrpe (N-(R)-(l-phenylethyl)glycine), Nsmb (N-(S)-(l -methyl butyl)glycine). Nsna (N-(S)-(l-naphthylethyl)glycine), Nspe (N-(S)-(l -phenylethyl) glycine), Nssb (N-(S)-(sec-butyl)glycine). Ntma (N-(2-thiophenemethyl)glycine), and Ntri (N -(tridecy l)gly cine).

[0042] Modifications to the C-terminal domain may be selected to prevent or decrease the formation of secondary structures or intrapeptide interactions that may contribute to amyloid formation. In some embodiments, a non / low amyloid-forming peptide analogue of the A|342 peptide can comprise a C-terminal domain wherein at least one position from 25 to 42 is replaced to prevent or decrease the formation of backbone hydrogen bonds, and / or to alter hydrophobicity in that domain. In some embodiments, position 29 to 36 are substituted, as they are hypothesized to be within the hydrophobic cavity. In a non-limiting example, such a substitution may involve replacing a hydrophobic residue with a charged or polar amino acid or amino acid analogue. In some embodiments, a substitution is selected that alters the conformation of the peptide backbone. In a non-limiting example, such a substitution may involve replacing a residue at a selected position with a proline, a D-amino acid, or amino acid analogue.

[0043] In some embodiments, the modified C-terminal domain can comprise a modification to the C-terminus, where said modification may impart useful enhancements to the peptide analogue as compared to the native Ap42 peptide. These enhancements can include, without limitation, one or more of increased circulation time, enhanced protease resistance and increased CSF half-life. It will be understood that these properties may be interrelated, i.e., decreased susceptibility to proteolysis can result in the analogue remaining functionally intact in the CSF for a longer period of time after administration, and therefore circulating in the CSF for a longer duration. Furthermore, these benefits can be amplified by enhancements resulting from other modifications, such as decreased beta-sheet formation, which results in reduced sequestration of functional peptide / analogue into amyloid structures. In some aspects, these enhancements can reduce the amount of analogue needed to bring about a desired therapeutic effect. Accordingly, the analogues described herein can provide for a reduced therapeutically effective amount as compared to the native A(342 peptide. It will be further understood that increased solubility resulting from other modifications can provide for a higher concentration of analogue in a solventbased therapeutic composition. As a result, a lower volume of the composition can be administered to a subject to produce a therapeutic effect.

[0044] In some of these embodiments, the C-terminus may be modified into an amide, N- alkyl amide, cysteamide, ester, aldehyde, hydrazide or hydroxamic acid. In various embodiments, modifications to the C-terminus may be combined with modifications to the C-terminal domain that, either alone or through combination with the modification to the C- terminus, impart useful properties to the peptide analogue. Exemplary groups for C- terminus modifications include, without limitation: amides, including N-alkyl amides;esters, including alkyl esters; alcohols; hydrazides; aldehydes; and hydroxamic acids. For example, the C-terminus may be modified into an amide, N-alkyl amide, cysteamide, ester, aldehyde, hydrazide or hydroxamic acid to enhance circulation time, protease resistance and / or CSF half-life together with a proline substitution in C-terminal domain (positions 25- 42) to decrease the propensity for beta-sheet stacking and amyloid formation. In still other variations, the C-terminus may be modified to an amide, N-alkyl amide, cysteamide, ester, aldehyde, hydrazide or hydroxamic acid to enhance circulation time, protease resistance and / or CSF half-life together with one or more charged or polar amino acid substitution(s) in the C-terminal domain (positions 25-42) to decrease propensity for beta-sheet stacking and amyloid formation and to enhance peptide solubility and to reduce therapeutically effective amount and / or administration volume. In still other variations, the C-terminus may be modified into an amide, N-alkyl amide, cysteamide, ester, aldehyde, hydrazide or hydroxamic acid to enhance circulation time and CSF half-life, together with one or more nonnatural charged amino acid substitution(s) in the C-terminal domain (positions 25-42) to decrease the propensity for beta-sheet stacking and amyloid formation, to enhance peptide solubility, to reduce therapeutically effective amount and / or administration volume and / or to enhance circulation time and protease resistance. The C-terminus may also be modified into an amide, N-alkyl amide, cysteamide. ester, aldehyde, hydrazide or hydroxamic acid to enhance circulation time and CSF half-life, together with one or more peptoid substitution(s) in the C-terminal domain (positions 25-42) to decrease the propensity for beta-sheet stacking and amyloid formation, to enhance protease resistance, to increase circulation time and / or to increase CSF half-life. In still other variations, the C-terminus may be modified into an amide, N-alkyl amide, cysteamide, ester, aldehyde, hydrazide or hydroxamic acid to enhance circulation time and CSF half-life, together with one or more charged peptoid substitution(s) in the C-terminal domain (positions 25-42) to decrease the propensity for beta-sheet stacking and amyloid formation, to enhance peptide solubility and to reduce therapeutically effective amount and / or administration volume, to enhance protease resistance, to enhance circulation time, and / or to increase CSF half-life. C- terminal domain modifications and C-terminus modifications may act together in an additive or synergistic fashion in producing an enhancement.

[0045] Sequences of the A[342 peptide and analogues thereof according to various specific embodiments are presented in FIGS 1A-1JJJ. As shown in FIG. 1A the wild-ty pe sequence of the A042 peptide is as set forth in SEQ ID NO: 1 and comprises an N-terminal domain, a middle domain and a C-terminal domain as described above. The C-terminal domains in the analogues SEQ ID NOS: 2-1660 comprise modifications of the SEQ ID NO: 1 that include:a. deletions of one to 13 amino acids from the C-terminal domain (SEQ ID NOS: 2-15. 205-208); or b. a substitution of one or more amino acids at positions 25-42 with: i. an amino acid selected from P, G, K, R, H. E, D, S, T, N, Q, and C; or ii. an amino acid analogue selected from: carboxyglutamic acid (CGA), D- proline (P*), N-methyl leucine (NML), N-(4-aminobutyl) glycine (NAG), N-(2- carboxyethyl) glycine (NCG), N-hydroxy methionine (NHM), N-methyl methionine (NMM), octenyl alanine (OA) and pyroglutamic acid (PGA) (SEQ ID NOS: 16-204, 209-214).

[0046] In some cases as illustrated by SEQ ID NO: 189, the N-terminal aspartic acid is modified to palmitoyl aspartate (D*). As also shown in FIGS 1A-1JJJ, in various further embodiments (SEQ ID NOS:215-1660) the C-terminus of the A(342 peptide and analogues thereof is modified into an amide, N-methyl amide (NMA), cysteamide (CA), methyl ester (ME), aldehyde (Aid), hydrazide (Hyd) or hydroxamic acid (HA). The use of modifications to create non / low amyloid-forming Ap42 peptide analogues may be clearly understood by the following discussion of various example embodiments.

[0047] In an embodiment, an Ap42 peptide analogue (SEQ ID NO: 86) comprises a substitution of proline for methionine at position 35 of Ap42. In another embodiment, the C-terminus of SEQ ID NO:86 is modified into an amide (SEQ ID NO:300). In another embodiment, the C-terminus of SEQ ID NO: 86 is modified into an N-methyl amide (SEQ ID NO:514). In another embodiment, the C-terminus of SEQ ID NO:86 is modified into a cysteamide (SEQ ID NO:720). In another embodiment, the C-terminus of SEQ ID NO:86 is modified into a methyl ester (SEQ ID NO:926). In another embodiment, the C-terminus of SEQ ID NO:86 is modified into an aldehyde (SEQ ID NO: 1132). In another embodiment, the C-terminus of SEQ ID NO:86 is modified into a hydrazide (SEQ ID NO: 1338). In another embodiment, the C-terminus of SEQ ID NO: 86 is modified into hydroxamic acid (SEQ ID NO: 1544). As discussed above, the substitution may confer on the modified analogue one or more enhancements selected from decreased propensity for beta-sheet stacking and amyloid formation, increased stability, and enhanced solubility. In each of the above embodiments comprising a C-terminus modification, said modification may confer on the modified analogue one or more enhancements selected from enhanced circulation time, protease resistance and CSF half-life. As a result of these enhancements, the therapeutically effective amount of the analogue may be reduced.

[0048] In an embodiment, an Ap42 peptide analogue (SEQ ID NO: 188) comprises a substitution of pyrrolysine for methionine at position 35 of Ap42. In another embodiment,the C-terminus of SEQ ID NO: 188 is modified into an amide (SEQ ID NO:402). In another embodiment, the C-terminus of SEQ ID NO: 188 is modified into an N-methyl amide (SEQ ID NO:616). In another embodiment, the C-terminus of SEQ ID NO: 188 is modified into a cysteamide (SEQ ID NO:822). In another embodiment, the C-terminus of SEQ ID NO: 188 is modified into a methyl ester (SEQ ID NO: 1028). In another embodiment, the C-terminus of SEQ ID NO: 188 is modified into an aldehyde (SEQ ID NO: 1234). In another embodiment, the C-terminus of SEQ ID NO: 188 is modified into a hydrazide (SEQ ID NO: 1440). In another embodiment, the C-terminus of SEQ ID NO: 188 is modified into hydroxamic acid (SEQ ID NO: 1646). As discussed above, the substitution may confer on the modified analogue one or more enhancements selected from decreased propensity for beta-sheet stacking and amyloid formation, increased stability, and enhanced solubility. In each of the above embodiments comprising a C-terminus modification, said modification may confer on the modified analogue one or more enhancements selected from enhanced circulation time, protease resistance and CSF half-life. As a result of these enhancements, the therapeutically effective amount of the analogue may be reduced.

[0049] In an embodiment, an Ap42 peptide analogue (SEQ ID NO:203) comprises a substitution of N-(4-aminobutyl)glycine for methionine at position 35 of A 42. In other embodiments, the C-terminus of SEQ ID NO:203 is respectively modified into an amide (SEQ ID NO:417), N-methyl amide (SEQ ID NO:623), cysteamide (SEQ ID NO:829), methyl ester (SEQ ID NO: 1035), aldehyde (SEQ ID NO:1241), hy drazide (SEQ ID NO: 1447), hydroxamic acid (SEQ ID NO: 1649). As discussed above, the substitution may confer on the modified analogue one or more enhancements selected from decreased propensity for beta-sheet stacking and amyloid formation, increased stability, and enhanced solubility. In each of the above embodiments comprising a C-terminus modification, said modification may confer on the modified analogue one or more enhancements selected from enhanced circulation time, protease resistance and CSF half-life. As a result of these enhancements, the therapeutically effective amount of the analogue may be reduced.

[0050] In an embodiment, an A[342 peptide analogue (SEQ ID NO:204) comprises a substitution of N-(2-carboxyethyl)glycine for methionine at position 35 of A[342. In other embodiments, the C-terminus SEQ ID NO:204 is respectively modified into an amide (SEQ ID NO:418), N-methyl amide (SEQ ID NO:624), cysteamide (SEQ ID NO:830), methyl ester (SEQ ID NO: 1036), aldehyde (SEQ ID NO: 1242), hydrazide (SEQ ID NO: 1448) or hydroxamic acid (SEQ ID NO: 1650). As discussed above, the substitution may confer on the modified analogue one or more enhancements selected from decreased propensity for beta-sheet stacking and amyloid formation, increased stability, and enhanced solubility. Ineach of the above embodiments comprising a C-terminus modification, said modification may confer on the modified analogue one or more enhancements selected from enhanced circulation time, protease resistance and CSF half-life. As a result of these enhancements, the therapeutically effective amount of the analogue may be reduced.

[0051] In an embodiment, an Ap42 peptide analogue (SEQ ID NO: 87) comprises a substitution of glycine for methionine at position 35 of A[342. In other embodiments, the C- terminus of SEQ ID NO:87 is respectively modified into an amide (SEQ ID NO:301), N- methyl amide (SEQ ID NO:515). cysteamide (SEQ ID NO:721). methyl ester (SEQ ID NO:927), aldehyde (SEQ ID NO: 1133), hydrazide (SEQ ID NO: 1339) or hydroxamic acid (SEQ ID NO: 1545). As discussed above, the substitution may confer on the modified analogue one or more enhancements selected from decreased propensity for beta-sheet stacking and amyloid formation, increased stability, and enhanced solubility. In each of the above embodiments comprising a C-terminus modification, said modification may confer on the modified analogue one or more enhancements selected from enhanced circulation time, protease resistance and CSF half-life. As a result of these enhancements, the therapeutically effective amount of the analogue may be reduced.

[0052] In an embodiment, an Ap42 peptide analogue (SEQ ID NO: 88) comprises a substitution of lysine for methionine at position 35 of Ap42. In other embodiments, the C- terminus of SEQ ID NO:88 is respectively modified into an amide (SEQ ID NO:302), N- methyl amide (SEQ ID NO:516). cysteamide (SEQ ID NO:722). methyl ester (SEQ ID NO:928), aldehyde (SEQ ID NO: 1134), hydrazide (SEQ ID NO:1340) or hydroxamic acid (SEQ ID NO: 1546). As discussed above, the substitution may confer on the modified analogue one or more enhancements selected from decreased propensity for beta-sheet stacking and amyloid formation, increased stability, and enhanced solubility. In each of the above embodiments comprising a C-terminus modification, said modification may confer on the modified analogue one or more enhancements selected from enhanced circulation time, protease resistance and CSF half-life. As a result of these enhancements, the therapeutically effective amount of the analogue may be reduced.

[0053] In an embodiment, an Ap42 peptide analogue (SEQ ID NO: 89) comprises a substitution of arginine for methionine at position 35 of Ap42. In other embodiments, the C-terminus of SEQ ID NO:89 is respectively modified into an amide (SEQ ID NO:303), N- methyl amide (SEQ ID NO: 517). cysteamide (SEQ ID NO: 723). methyl ester (SEQ ID NO:929), aldehyde SEQ ID NO: 1135), hydrazide (SEQ ID NO: 1341) or hydroxamic acid (SEQ ID NO: 1547). As discussed above, the substitution may confer on the modified analogue one or more enhancements selected from decreased propensity for beta-sheetstacking and amyloid formation, increased stability, and enhanced solubility. In each of the above embodiments comprising a C-terminus modification, said modification may confer on the modified analogue one or more enhancements selected from enhanced circulation time, protease resistance and CSF half-life. As a result of these enhancements, the therapeutically effective amount of the analogue may be reduced.

[0054] In an embodiment, an Ap42 peptide analogue (SEQ ID NO:90) comprises a substitution of histidine for methionine at position 35 of Ap42. In other embodiments, the C-terminus of SEQ ID NO:90 is respectively modified into an amide (SEQ ID NO:304). N- methyl amide (SEQ ID NO:518), cysteamide (SEQ ID NO:724), methyl ester (SEQ ID NO:930), aldehyde (SEQ ID NO: 1136), hydrazide (SEQ ID NO:1342) or hydroxamic acid (SEQ ID NO: 1548). As discussed above, the substitution may confer on the modified analogue one or more enhancements selected from decreased propensity for beta-sheet stacking and amyloid formation, increased stability, and enhanced solubility. In each of the above embodiments comprising a C-terminus modification, said modification may confer on the modified analogue one or more enhancements selected from enhanced circulation time, protease resistance and CSF half-life. As a result of these enhancements, the therapeutically effective amount of the analogue may be reduced.

[0055] In an embodiment, an Ap42 peptide analogue (SEQ ID NO:91) comprises a substitution of glutamic acid for methionine at position 35 of A 42. In other embodiments, the C-terminus of SEQ ID NO:91 is respectively modified into an amide (SEQ ID NO:305). N-methyl amide (SEQ ID NO:519), cysteamide (SEQ ID NO:725), methyl ester (SEQ ID NO:931), aldehyde (SEQ ID NO: 1137), hydrazide (SEQ ID NO:1343) or hydroxamic acid (SEQ ID NO: 1549). As discussed above, the substitution may confer on the modified analogue one or more enhancements selected from decreased propensity for beta-sheet stacking and amyloid formation, increased stability, and enhanced solubility. In each of the above embodiments comprising a C-terminus modification, said modification may confer on the modified analogue one or more enhancements selected from enhanced circulation time, protease resistance and CSF half-life. As a result of these enhancements, the therapeutically effective amount of the analogue may be reduced.

[0056] In an embodiment, an Ap42 peptide analogue (SEQ ID NO: 92) comprises a substitution of aspartic acid for methionine at position 35 of Ap42. In other embodiments, the C-terminus of SEQ ID NO:92 is respectively modified into an amide (SEQ ID NO:306). N-methyl amide (SEQ ID NO:520), cysteamide (SEQ ID NO:726), methyl ester (SEQ ID NO:932), aldehyde (SEQ ID NO: 1138), hydrazide (SEQ ID NO:1344) or hydroxamic acid (SEQ ID NO: 1550). As discussed above, the substitution may confer on the modifiedanalogue one or more enhancements selected from decreased propensity for beta-sheet stacking and amyloid formation, increased stability, and enhanced solubility. In each of the above embodiments comprising a C-terminus modification, said modification may confer on the modified analogue one or more enhancements selected from enhanced circulation time, protease resistance and CSF half-life. As a result of these enhancements, the therapeutically effective amount of the analogue may be reduced.

[0057] In an embodiment, an Ap42 peptide analogue (SEQ ID NO: 93) comprises a substitution of serine for methionine at position 35 of Ap42. In other embodiments, the C- terminus of SEQ ID NO:93 is respectively modified into an amide (SEQ ID NO:307), N- methyl amide (SEQ ID NO:521), cysteamide (SEQ ID NO:727), methyl ester (SEQ ID NO:933), aldehyde (SEQ ID NO: 1139), hydrazide (SEQ ID NO:1345) or hydroxamic acid (SEQ ID NO: 1551). As discussed above, the substitution may confer on the modified analogue one or more enhancements selected from decreased propensity for beta-sheet stacking and amyloid formation, increased stability, and enhanced solubility. In each of the above embodiments comprising a C-terminus modification, said modification may confer on the modified analogue one or more enhancements selected from enhanced circulation time, protease resistance and CSF half-life. As a result of these enhancements, the therapeutically effective amount of the analogue may be reduced.

[0058] In an embodiment, an Ap42 peptide analogue (SEQ ID NO: 94) comprises a substitution of threonine for methionine at position 35 of A 42. In other embodiments, the C-terminus of SEQ ID NO:94 is respectively modified into an amide (SEQ ID NO:308), N- methyl amide (SEQ ID NO:522), cysteamide (SEQ ID NO:728), methyl ester (SEQ ID NO:934), aldehyde (SEQ ID NO: 1140), hydrazide (SEQ ID NO:1346) or hydroxamic acid (SEQ ID NO: 1552). As discussed above, the substitution may confer on the modified analogue one or more enhancements selected from decreased propensity for beta-sheet stacking and amyloid formation, increased stability, and enhanced solubility. In each of the above embodiments comprising a C-terminus modification, said modification may confer on the modified analogue one or more enhancements selected from enhanced circulation time, protease resistance and CSF half-life. As a result of these enhancements, the therapeutically effective amount of the analogue may be reduced.

[0059] In an embodiment, an Ap42 peptide analogue (SEQ ID NO: 95) comprises a substitution of asparagine for methionine at position 35 of A 42. In other embodiments, the C-terminus of SEQ ID NO:95 is respectively modified into an amide (SEQ ID NO:309), N- methyl amide (SEQ ID NO:523), cysteamide (SEQ ID NO:729), methyl ester (SEQ ID NO:935), aldehyde (SEQ ID NO: 1141), hydrazide (SEQ ID NO:1347) or hydroxamic acid(SEQ ID NO: 1553). As discussed above, the substitution may confer on the modified analogue one or more enhancements selected from decreased propensity for beta-sheet stacking and amyloid formation, increased stability, and enhanced solubility. In each of the above embodiments comprising a C-terminus modification, said modification may confer on the modified analogue one or more enhancements selected from enhanced circulation time, protease resistance and CSF half-life. As a result of these enhancements, the therapeutically effective amount of the analogue may be reduced.

[0060] In an embodiment, an A[342 peptide analogue (SEQ ID NO:96) comprises a substitution of glutamine for methionine at position 35 of AP42. In other embodiments, the C-terminus of SEQ ID NO:96 is respectively modified into an amide (SEQ ID NO:310), N- methyl amide (SEQ ID NO:524), cysteamide (SEQ ID NO:730), methyl ester (SEQ ID NO:936), aldehyde (SEQ ID NO: 1142), hydrazide (SEQ ID NO: 1348) or hydroxamic acid (SEQ ID NO: 1554). As discussed above, the substitution may confer on the modified analogue one or more enhancements selected from decreased propensity for beta-sheet stacking and amyloid formation, increased stability, and enhanced solubility. In each of the above embodiments comprising a C-terminus modification, said modification may confer on the modified analogue one or more enhancements selected from enhanced circulation time, protease resistance and CSF half-life. As a result of these enhancements, the therapeutically effective amount of the analogue may be reduced.

[0061] In an embodiment, an A[342 peptide analogue (SEQ ID NO:97) comprises a substitution of cysteine for methionine at position 35 of A042. In other embodiments, the C-terminus of SEQ ID NO:97 is respectively modified into an amide (SEQ ID NO:311), N- methyl amide (SEQ ID NO:525), cysteamide (SEQ ID NO:731), methyl ester (SEQ ID NO:937), aldehyde (SEQ ID NO: 1143), hydrazide (SEQ ID NO: 1349) or hydroxamic acid (SEQ ID NO: 1555). As discussed above, the substitution may confer on the modified analogue one or more enhancements selected from decreased propensity for beta-sheet stacking and amyloid formation, increased stability, and enhanced solubility. In each of the above embodiments comprising a C-terminus modification, said modification may confer on the modified analogue one or more enhancements selected from enhanced circulation time, protease resistance and CSF half-life. As a result of these enhancements, the therapeutically effective amount of the analogue may be reduced.

[0062] In an embodiment, an A[342 peptide analogue (SEQ ID NO: 98) comprises a substitution of proline for valine at position 36 of A()42. In other embodiments, the C- terminus of SEQ ID NO:98 is respectively modified into an amide (SEQ ID NO:312), N- methyl amide (SEQ ID NO:526), cysteamide (SEQ ID NO:732), methyl ester (SEQ IDNO:938), aldehyde (SEQ ID NO: 1144), hydrazide (SEQ ID NO: 1350) or hydroxamic acid (SEQ ID NO: 1556). As discussed above, the substitution may confer on the modified analogue one or more enhancements selected from decreased propensity for beta-sheet stacking and amyloid formation, increased stability, and enhanced solubility'. In each of the above embodiments comprising a C-terminus modification, said modification may confer on the modified analogue one or more enhancements selected from enhanced circulation time, protease resistance and CSF half-life. As a result of these enhancements, the therapeutically effective amount of the analogue may be reduced.

[0063] In an embodiment, an A[342 peptide analogue (SEQ ID NO: 186) comprises a substitution of N-methyl methionine for methionine at position 35 of A|342. In other embodiments, the C-terminus of SEQ ID NO: 186 is respectively modified into an amide (SEQ ID NO:400), N-methyl amide (SEQ ID NO:614). cysteamide (SEQ ID NO:820). methyl ester (SEQ ID NO: 1026), aldehyde (SEQ ID NO: 1232), hydrazide (SEQ ID NO: 1438) or hydroxamic acid (SEQ ID NO: 1644). As discussed above, the substitution may confer on the modified analogue one or more enhancements selected from decreased propensity for beta-sheet stacking and amyloid formation, increased stability, and enhanced solubility. In each of the above embodiments comprising a C-terminus modification, said modification may confer on the modified analogue one or more enhancements selected from enhanced circulation time, protease resistance and CSF half-life. As a result of these enhancements, the therapeutically effective amount of the analogue may be reduced.

[0064] Non / low amyloid-forming analogue of A|342 peptides as described herein can be manufactured using standard solution phase methodology. Suitable synthesis methodologies include solid phase peptide synthesis, liquid phase peptide synthesis, microwave-assisted peptide synthesis, In an exemplary method, the analogue is generated using a solid phase peptide synthesis (SPPS) method. SPPS is a well-established methodology (see for example: Solid-phase peptide synthesis: from standard procedures to the synthesis of difficult sequences. Coin I. et al., Nature Protocols, 2007 or Methods and protocols of modem solid phase peptide synthesis. Amblard M. et al.. Molecular Biotechnology, 2006). SPPS is initiated by attaching the carboxy group of an N-terminally protected amino acid to an inert solid support carrying a cleavable linker. The two standard protecting groups for a- amino functions of the coupled amino acids are 9-fluorenylmethyloxy carbonyl group (Fmoc) and t-butyloxycarbonyl (Boc). The solid support can be any polymer that allows coupling of the initial amino acid, e.g., a trityl resin, a chlorotrityl resin, a Wang resin or a Rink resin in which the linkage of the carboxy group (or carboxamide for Rink resin) to the resin is sensitive to acid (when Fmoc strategy is used). The polymer support must be stableunder the conditions used to deprotect the a-amino group during the peptide synthesis. After the first amino acid has been coupled to the solid support, the a-amino protecting group of this amino acid is removed. The remaining protected amino acids are then coupled one after the other in the order represented by the peptide sequence using appropriate amide coupling reagents, for example BOP (benzotriazole- l-yl-oxy-tris-(dimethylamino)-phosphonium hexafluorophosphate), HBTU (2-(lH-benzotriazole-l-yl)-l,l,3,3-tetramethyluronium hexafluorophosphate), HATU (l-[bis(dimethylamino)methylene]-lH-l,2,3-triazolo[4,5- b]pyridinium 3-oxid hexafluorophosphate) or DIC (N,N'-diisopropylcarbodiimide) / HOBt (1-hydroxybenzotriazol), wherein BOP, HBTU and HATU are used with tertiary amine bases. Alternatively, the liberated N-terminus can be functionalized with groups other than amino acids, for example carboxylic acids, etc. Usually, reactive side-chain groups of the amino acids are protected with suitable blocking groups. These protecting groups are removed after the desired peptides have been assembled. They are removed concomitantly with the cleavage of the desired product from the resin under the same conditions. Protecting groups and the procedures to introduce protecting groups can be found in Protecting Groups in Peptide Synthesis. Conda-Sheridan M. et aL, Methods Mol Biol, 2020.

[0065] C-terminus amidation can be performed using benzhydrylamine resins as solid support, and other C-terminus modifications can be performed using established protocols (see for example: Recent advances in the synthesis of C-terminally modified peptides, Arbour C. et al., Org Biomol Chem. 2020). The synthesized peptide is cleaved from the resin, which can be achieved by using King's cocktail (consisting of 82.5% trifluoroacetic acid (TFA), 5% phenol, 5% water, 5% thioanisole, 2.5% ethanedithiol). The raw material can then be purified by chromatography, e.g., preparative RP-HPLC, if necessary. Peptides are then analyzed by analytical HPLC and checked for the correct mass by mass spectrometry. Ion exchange of the residual TFA ions to chloride or acetate can sometimes be performed.

[0066] In some embodiments, a nucleic acid encoding the peptide analogues is provided. In particular embodiments the nucleic acid encodes a sequence selected from SEQ ID NOS: 190 and 201. The nucleic acid can be e.g., DNA or RNA (such as mRNA) that can be transcribed and / or translated by cellular machinery to produce the desired engineered protein in vivo. Any suitable method of genetic engineering (e.g. transfection of cells obtained from and then reintroduced into the body, CRISPR-Cas gene editing, introduction of a suitable viral vector into target cells, or the like) and / or nucleic acid delivery’ system (e.g. lipid nanoparticles, which can be used to deliver CRISPR-Cas gene editing systems, mRNA or viral vectors to target cells) can be used to supply the nucleic acid encoding theengineered peptide to the desired target cells. Any methods now known or developed in future for causing desired cells to express a desired peptide could be used in various embodiments to cause cells to express the desired non-aggregating engineered protein. In some embodiments, including embodiments in which the engineered peptide incorporates a non-naturally occurring amino acid analogue, the engineered peptide is chemically modified.

[0067] A pharmaceutical composition for treating or preventing A(342 proteinopenia can comprise a therapeutically effective amount of a non / low amyloid-forming analogue of A(342 peptide as described herein or a pharmaceutically acceptable salt thereof. In some embodiments, the analogue may be in the form of a prodrug configured to yield the analogue by solvolysis or under physiological conditions. In some embodiments, the pharmaceutical composition can be formulated for parenteral administration such as by intrathecal, intravenous, intramuscular, or subcutaneous injection or infusion. For example, the composition can be formulated with a pharmaceutically acceptable vehicle or diluent.

[0068] Exemplary compositions for parenteral administration can contain, for example, suitable non-toxic, parenterally acceptable diluents or solvents, such as mannitol, 1,3- butanediol, water, Ringer's solution, an isotonic sodium chloride solution, or other suitable dispersing or wetting and suspending agents. Pharmaceutically acceptable compositions may include one or more co-solvents including, but not limited to ethanol, N.N dimethylacetamide, propylene glycol, glycerol and polyethylene glycols, e.g., polyethylene glycol 300 and / or polyethylene glycol 400. Surfactants may be used including, without limitation, d-a-Tocopheryl polyethlene glycol 1000 succinate (TPGS), Solutol HS 15, polysorbate 80, polysorbate 20, poloxamer, pyrrolidones such as N-alkylpyrrolidone (e.g., N-methylpyrrolidone) and / or polyvinylpyrrolidone. The formulation may also comprise use of one or more buffers including, without limitation, sodium phosphate, sodium citrate, diethanolamine, triethanolamine, L-arginine, L-lysine, L-histidine, L-alanine, glycine, sodium carbonate, tromethamine (a / k / a tris [hydroxymethyl] aminomethane or Tris), and / or mixtures thereof.

[0069] Methods of treating or preventing A(342 proteinopenia in a subject are encompassed by the present disclosure. In some embodiments, a method of treating or preventing A(342 proteinopenia in a subject can comprise administering to the subject a therapeutically effective amount of a non / low amyloid-forming analogue of A[342 peptide as described herein. In some embodiments, such a method can comprise directly administering to the subject a therapeutically effective amount of a composition comprising the analogue or apharmaceutically acceptable salt thereof. In some embodiments, the subject is a mammalian subject. In more particular embodiments, the subject is a human.

[0070] In some embodiments, treatment may follow screening the subject to determine whether the subject is a candidate for treatment and / or prophylaxis of a proteinopathy using a non / low amyloid-forming analogue of A|342 peptide are encompassed by the present disclosure. In some embodiments, the method comprises determining a concentration of Ap42 in the CSF of the subject. If the measured concentration of Ap42 in the CSF is less than about 500 pM. less than about 400 pM, less than about 300 pM, or less than about 200 pM, including e.g. less than about 175, 150, 125 or 100 pM, then the subject is identified as a candidate for treatment or prophylaxis via the administration of a non / low amyloid-forming analogue of Ap42 peptide as described herein. In some such embodiments, the concentration of Ap42 in the cerebrospinal fluid of the subject is determined using an immunoassay or liquid chromatography -tandem mass spectrometry.

[0071] In various embodiments, therapeutic compositions comprising engineered peptides that are non / low amyloid-forming analogues of the AP42 peptide or nucleic acids encoding such peptides as described herein are administered in any suitable manner now known or developed in future, including direct administration, genetic engineering techniques, liposome-mediated delivery' including lipid nanoparticle delivery', viral vectors or the like. Modes of direct administration can include subcutaneous, intravenous, intracerebroventricular, intracerebral, intrathecal, intraperitoneal, intramuscular or intravenous injection, infusion, or topical, nasal, oral (including sublingual or buccal), rectal, ocular or otic, or other form of delivery', including pumping or direct injection into the brain of a subject. Modes of liposome-mediated delivery can include direct delivery of the engineered peptide or a nucleic acid (e.g., mRNA) encoding the engineered peptide for expression by a cell, or DNA encoding the engineered peptide together with suitable mechanisms (e.g. CRISPR-Cas gene editing systems) to integrate the DNA into the genome of the cell to facilitate expression of the engineered peptide by the cell, or using a viral vector as an expression module for the desired peptide.

[0072] In some embodiments, the amount of peptide analogue to be administered or caused to be expressed can be determined by a person skilled in the art dependent on the condition to be treated and the mode of administration. In some embodiments, the interval of administration of the analogue can be determined by7a person skilled in the art dependent on the condition to be treated and the mode of administration. In some embodiments the amount of analogue to be administered or caused to be expressed is sufficient to provide aconcentration of the analogue in the CSF of a subject of about 200 to about 600 pg / mL, including any value or subrange therebetween, e.g. 250, 300, 350, 400, 450, 500 or 550 pg / mL. In some embodiments, the amount of analogue to be administered or caused to be expressed is less than an amount of native A|342 peptide that would be administered to achieve the same therapeutic effect.EXAMPLE

[0073] The A(342 peptide analog SEQ ID NO:400 is generated by the following process:1. Load rink amide resin: Rink amide resin is used to produce the C-terminally amidated peptide. Weigh 300 mg for a 0.1 mmol scale synthesis. Add the resin to an appropriate chromatography column. Swell resin for 1 hour in N,N-dimethylformamide (DMF) .2. Use nitrogen gas to rinse the column.3. Cleave the Fmoc from the resin using 10 mL of 20% (v / v) piperidine in DMF. Shake the resin in the 20% piperidine solution for 1 h.4. Use nitrogen gas to rinse the column.5. Wash the resin 3X with DMF.6. Activate the 1stamino acid from the C-terminus (Fmoc-Ala-OH) by mixing 5 equivalents with 4.5 equivalents of HATU and 4.5 equivalents of HOAt in a glass scintillation vial together with 10 ml of 20% A-methylmorphiline (v / v) in DMF.7. Add the activated amino solution onto the resin and shake at room temperature for 4 h.8. Use nitrogen gas to rinse the column.9. Wash 3X with DMF.10. Cap the rink amide resin by using a capping solution (acetic anhydride and pyridine in a 3:2 ratio). Add the capping solution on the resin and shake for 30 min.11. Use nitrogen gas to rinse the column.12. Wash 3X with DMF.13. Cleave the Fmoc using 10 mL of 20% (v / v) piperidine in DMF. Shake the resin in the 20% piperidine solution for 1 h.14. Use nitrogen gas to rinse the column.15. Wash the resin 3X with DMF.16. Repeat steps 6-15 with each of the following protected amino acids in the order presented:17. Final cleavage from the resin: Wash the completed peptide on resin 3X with CH2CI2, and transfer it into a poly prep column.18. Dry the resin under a stream on N2 gas for 1 h.19. Add 10 mL of an 18: 1 :1 TFA:H2O:TIPS (prepared by adding 9 mL TFA and 0.5 mL of both H2O and TIPS) to the resin and shake for 1.5 hours.20. Collect solution in a 250-mL round bottom flask.21. Evaporate the TFA on a rotovap and transfer the peptide for lyophilization.

[0074] The claims following this written disclosure are hereby expressly incorporated into the present written disclosure, with each claim standing on its own as a separate embodiment. This disclosure includes all permutations of the independent claims with their dependent claims. Moreover, additional embodiments capable of derivation from the independent and dependent claims that follow are also expressly incorporated into the present written description.

[0075] Without further elaboration, it is believed that one skilled in the art can use the preceding description to utilize the invention to its fullest extent. The claims and embodiments disclosed herein are to be construed as merely illustrative and exemplary, and not a limitation of the scope of the present disclosure in any way. It will be apparent to those having ordinary skill in the art, with the aid of the present disclosure, that changes may be made to the details of the abovedescribed embodiments without departing from the underlying principles of the disclosure herein. In other words, various modifications and improvements of the embodiments specifically disclosed in the description above are within the scope of the appended claims. Moreover, the order of the steps or actions of the methods disclosed herein may be changed by those skilled in the art without departing from the scope of the present disclosure. In other words, unless a specific order of steps or actions is required for proper operation of the embodiment, the order or use of specific steps or actions may be modified. The scope of the invention is therefore defined by the following claims and their equivalents.

Claims

CLAIMSWhat is claimed is:

1. An Ap peptide analogue for the treatment or prevention of Ap proteinopenia, comprising: an N-terminal domain corresponding to positions 1-18 of SEQ ID NO: 1; a middle domain corresponding to positions 19-24 of SEQ ID NO:1; and a C-terminal domain corresponding to positions 25-42 of SEQ ID NO: 1, and including a modification comprising: deletion of 1-13 amino acids; or at least one of: a C-terminus modification comprising an amide, N-alkyl amide, cysteamide, ester, aldehyde, hydrazide or hydroxamic acid; and a C-terminal domain substitution comprising an amino acid, an amino acid analogue, or both.

2. The Ap peptide analogue of claim 1, wherein the N-terminal domain has at least 85% identity to positions 1-18 of SEQ ID NO:

13. The Ap peptide analogue of claim 1 or 2, wherein the middle domain has at least 85% identity to positions 19-24 of SEQ ID NO : 1.

4. The A peptide analogue of claim 1 or 2, wherein the C-terminus modification is an amide.

5. The Ap peptide analogue of claim 1 or 2, wherein the C-terminus modification is N-alkyl amide.

6. The Ap peptide analogue of claim 1 or 2, wherein the C-terminus modification is cysteamide.

7. The Ap peptide analogue of claim 1 or 2, wherein the C-terminus modification is an ester.

8. The Ap peptide analogue of claim 1 or 2, wherein the C-terminus modification is an aldehyde.

9. The Ap peptide analogue of claim 1 or 2, wherein the C-terminus modification is a hydrazide.

10. The Ap peptide analogue of claim 1 or 2, wherein the C-terminus modification is hydroxamic acid.

11. The Ap peptide analogue of any one of claims 1 to 10, wherein the C-terminal domain substitution comprises one or more prolines.

12. The A peptide analogue of any one of claims 1 to 11, wherein the C-terminal domain substitution comprises one or more charged amino acids.

13. The Ap peptide analogue of any one of claims 1 to 12, wherein the C-terminal domain substitution comprises one or more polar amino acids.

14. The Ap peptide analogue of any one of claims 1 to 13, wherein the C-terminal domain substitution comprises one or more amino acids selected from the group consisting of proline, glycine, lysine, arginine, histidine, glutamic acid, aspartic acid, serine, threonine, asparagine, glutamine and cysteine.

15. The Ap peptide analogue of any one of claims 1 to 14, wherein the C-terminal domain substitution comprises one or more amino acid analogues selected from 3 -hydroxyproline, 4- hydroxyproline, selenocysteine, pyroglutamic acid, carboxyglutamic acid, octenyl alanine, pyrrolysine, palmitoyl aspartate, D-amino acids including D-proline, P-amino acids, y-amino acids, homo-amino acids, P-homo-amino acids, a-methyl amino acids, N-methyl amino acids, N-ethyl amino acids, N-alkylated amino acid derivatives (preferably with 1, 2 or 3 carbons in the alkyl moiety), peptoid substituents, pyruvic acid derivatives, branched-chain amino acid derivatives, nitro amino acid derivatives, halogenated amino acid derivatives, ring-substituted amino acid derivatives, aromatic amino acid derivatives, linear core amino acids, hydroxylated amino acid derivatives, cyclic amino acids, bicyclic amino acids, 3-amino-3-aryl-propionic acids, 3-amino-4-aryl-butyric acids, amino acids with aromatic spacers, alicyclic amino acids, a-phenylglycine derivatives.

16. The Ap peptide analogue of claim 15, wherein the one or more amino acid analogues are peptoid substituents selected from N-(2-aminoethyl)glycine, N-(2-aminohexyl)glycine, N-(2- furfuryl)glycine, N-(2-carboxyethyl)glycine), N-(methylimidazole)glycine, N-(4- aminobutyl)glycine, N-(4-(Ns, Ne,Ne-trimethylammonium)butyl)glycine, N-(2- methoxyethyl)glycine, N-(phenylmethyl)glycine, N-(R)-(l-phenylethyl)glycine, N-(S)-(1-methyl butyl)glycine, N-(S)-(l-naphthylethyl)glycine, N-(S)-(1 -phenylethyl) glycine, N-(S)- (sec-butyl)glycine, N-(2-thiophenemethyl)glycine), and N-(tridecyl)glycine.

17. The Ap peptide analogue of claim 15, wherein the one or more amino acid analogues are selected from carboxyglutamic acid, D-proline, N-methyl leucine, N-(4-aminobutyl) glycine, N-(2-carboxyethyl) glycine, N-hydroxy methionine, N-methyl methionine, octenyl alanine and pyroglutamic acid.

18. The A peptide analogue of any one of claims 1 to 17, wherein the Ap peptide analogue comprises an increased half-life in cerebrospinal fluid (CSF) relative to wild type Ap42 peptide.

19. The Ap peptide analogue of claim 18, wherein the half-life is at least about 10 min, at least about 20 min, at least about 30 min, at least about 40 min, or at least about 50 min.

20. The Ap peptide analogue of claim 18, wherein the half-life is at least about 1 hours, at least about 5 hours, or at least about 10 hours.

21. The Ap peptide analogue of claim 18, wherein the half-life is at least about 1 day, at least about 10 days, at least about 60 days, at least about 10 weeks, or at least about 50 weeks.

22. The Ap peptide analogue of claim 1 , wherein the Ap peptide analogue comprises an increased protease resistance relative to wild type Ap42 peptide.

23. The Ap peptide analogue of any one of claims 1 to 22, wherein the Ap peptide analogue has a decreased propensity for beta-sheet stacking and amyloid formation relative to wild type AP42 peptide.

24. The Ap peptide analogue of any one of claims 1 to 23, wherein the Ap peptide analogue comprises increased solubility in a liquid medium relative to wild type AP42 peptide.

25. The Ap peptide analogue of claim 24, wherein the medium is a pharmaceutically acceptable medium.

26. The Ap peptide analogue of claim 24, wherein the solubility is at least about 1 mg / ml, more preferably at least about 5 mg / ml and most preferably at least about 50 mg / ml.

27. The Ap peptide analogue of claim 18, wherein the half-life is at least about 1 hours, at least about 2 hours, at least about 3 hours, at least about 4 hours, at least about 5 hours, at least about 6 hours, at least about 7 hours, at least about 8 hours, at least about 9 hours, or at least about 10 hours.

28. The A peptide analogue of any one of claims 1 to 27, wherein the Ap peptide analogue performs a function of wild type Ap42 peptide to at least 50% of the level performed by wild type AP42 peptide.

29. The Ap peptide analogue of claim 28, wherein the function comprises inducing a 7 nicotinic acetylcholine receptor (a7nAChR) mediated Ca2+influx.

30. The Ap peptide analogue of claim 1, wherein the Ap peptide analogue is selected from the group consisting of SEQ ID NOS: 190-1660.

31. The Ap peptide analogue of claim 1, comprising (N-(4-aminobutyl)glycine) at position 34, position 35, or both.

32. The Ap peptide analogue of claim 31, wherein the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:203, 417, 623, 829, 1035, 1241, 1447 and 1649.

33. The Ap peptide analogue of claim 1 , comprising (N-(2-carboxyethyl)glycine) at position34. position 35, or both.

34. The Ap peptide analogue of claim 33, wherein the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:204, 418, 624, 830, 1034, 1242, 1448 and 1650.

35. The Ap peptide analogue of claim 1, wherein the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:300, 514, 720, 926, 1132, 1338 and 1544.

36. The Ap peptide analogue of claim 1, wherein the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:402, 616, 822, 1028, 1234, 1440 and 1646.

37. The Ap peptide analogue of claim 1, wherein the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:301, 515, 721, 927, 1133, 1339 and 1545.

38. The Ap peptide analogue of claim 1, wherein the A peptide analogue is selected from the group consisting of SEQ ID NOS:302, 516, 722, 928, 1134, 1340 and 1546.

39. The Ap peptide analogue of claim 1, wherein the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:303, 517, 723, 929, 1135, 1341 and 1547.

40. The Ap peptide analogue of claim 1, wherein the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:304, 518, 724, 930, 1136, 1342 and 1548.

41. The Ap peptide analogue of claim 1, wherein the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:305, 519, 725, 931, 1137, 1343 and 1549.

42. The Ap peptide analogue of claim 1, wherein the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:306, 520, 726, 932, 1138, 1344 and 1550.

43. The Ap peptide analogue of claim 1, wherein the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:307, 521, 727, 933, 1139, 1345 and 1551.

44. The Ap peptide analogue of claim 1, wherein the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:308, 522, 728, 934, 1140, 1346 and 1552.

45. The Ap peptide analogue of claim 1, wherein the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:309, 523, 729, 935, 1141, 1347 and 1553.

46. The Ap peptide analogue of claim 1, wherein the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:310, 524, 730, 936, 1142, 1348 and 1554.

47. The Ap peptide analogue of claim 1, wherein the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:311, 525, 731, 937, 1143, 1349 and 1555.

48. The Ap peptide analogue of claim 1, wherein the Ap peptide analogue is selected from the group consisting of SEQ ID NOS:400, 614, 820, 1026, 1232, 1438 and 1644.

49. A composition for treating or preventing Ap proteinopenia, comprising: a therapeutically effective amount of the Ap peptide analogue of any one of claims 1 to48 or a pharmaceutically acceptable salt thereof; and a pharmaceutically acceptable vehicle.

50. The composition of claim 49, wherein the composition is formulated for parenteral administration.

51. The composition of claim 50, wherein the composition is formulated for intrathecal administration.

52. A method of treating or preventing Ap proteinopenia in a subject, comprising administering to the subject a therapeutically effective amount of the Ap peptide analogue of any one of claims 1 to 48.

53. The method of claim 52, wherein the therapeutically effective amount is sufficient to provide a concentration of the analogue in the CSF of a subject of about 200 to about 600 pg / mL.

54. The method of claim 52, wherein the therapeutically effective amount is lower than that for wild type AP42 peptide.

55. The method of claim 52, comprising a prior step of identifying the subject as a candidate for treatment by determining a concentration of AP42 in the CSF of the subject.

56. A method of treating or preventing Ap proteinopenia in a subject, comprising administering to the subject one or both of a nucleic acid encoding SEQ ID NO: 190 and a nucleic acid encoding SEQ ID NO:200.

57. A nucleic acid encoding SEQ ID NO: 190 and a nucleic acid encoding SEQ ID NO:200.

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