68 results about "C-terminus" patented technology

Provided is a polypeptide which contains a polypeptide having at least 80%, 85%, 90%, 95%, or 99% identity to amino acid sequence MTYRPGYNPFG (SEQ ID NO: 41) or amino acid sequence AKGYYRPYGVPV (SEQ ID NO: 22), or a polypeptide having one or more amino acid substitutions, deletions and / or additions relative to the amino acid sequence as shown in SEQ ID NO: 41 or 22. The provided polypeptide can interfere with the binding of a Brag2 synaptic protein to the C terminus of an AMPA receptor, thereby inhibiting NMDA-mediated excessive endocytosis of an AMPA receptor and neuronal apoptosis, and playing a role in protecting neuronal cell activity. Therefore, the polypeptide has application prospects and potential development values as a drug for treating nervous system diseases such as strokes, depression, Alzheimer's disease and drug addiction.

The invention discloses decapeptide with antioxidant activity, the amino acid sequence of the decapeptide is amino terminal-APKTLPWGPK-carboxyl terminal, and the decapeptide can be developed into an antioxidant.

The application discloses a method for conformational signal peptide-mediated secretion and expression of heterologous proteins in Escherichia coli, and specifically comprises the following steps: simultaneously fusing at least two heterologous proteins to a conformational signal peptide (such as sfGFP) and constructing a heterologous recombinant protein expression vector, wherein the conformational signal peptide has a beta-barrel structure, and the fusion sites are at least two of the amino terminal end, the carboxyl terminal end and a plurality of loop rings of the conformational signal peptide; and then transforming the heterologous recombinant protein expression vector into Escherichia coli and culturing the obtained genetic engineering strain for expression. According to the method, the extracellular secretion and expression of the heterologous proteins in the Escherichia coli can be realized without the mediation of a classical signal peptide, the sfGFP as a fusion tag has no influence on the function of the target protein, and the corresponding target protein can be quickly expressed and purified; and the method expands the secretion and expression path of the protein, can realize the simultaneous expression of a plurality of heterologous proteins, and can effectively improve the expression amount of the target protein.

The invention provides a nanopore probe and application thereof, the nanopore probe comprises a polypeptide, the carboxyl terminal of the polypeptide is connected with a steric hindrance tag, the amino terminal of the polypeptide is connected with polyaspartic acid, and the polypeptide has a restriction enzyme cutting site specifically recognized by target protease. The method can prolong the retention time of the polypeptide in the nanopore, enhance the signal discernibility and improve the signal stability, thereby realizing stable and high-precision quantitative detection of the protease activity.

The invention belongs to the field of chemical synthesis, and particularly relates to a chemical synthesis method of elastin-like polypeptide. The invention provides a chemical synthesis method of elastin-like, which comprises the following steps of: constructing a pentapeptide repetitive sequence (valine-proline-glycine-X-glycine, X is amino acid except proline, and the amino acid except glycine is respectively and independently selected from levoamino acid or dextroamino acid) of elastin-like polypeptide through liquid phase reaction; the elastin-like polypeptide can be prepared with the target molecular weight of 1000-500000 by adding amino groups and carboxyl groups into an organic solvent, forming orthogonal protection on the amino groups and the carboxyl groups, then selectively removing amino or carboxyl end protecting groups respectively, accurately coupling the amino groups and the carboxyl groups in a solution and repeating the deprotection and coupling processes for multiple times. The preparation method can realize accurate regulation and control of the molecular weight, sequence, chirality and topological structure of the elastin-like protein, improves the synthesis efficiency of the high-molecular-weight elastin-like polypeptide, has the advantages of large synthesis scale, low cost and the like, and has a wide application prospect.

The present inventors succeeded in improving the antibody constant region to have increased stability under acid conditions, reduced heterogeneity originated from disulfide bonds in the hinge region, reduced heterogeneity originated from the H chain C terminus, and increased stability at high concentrations as well as in discovering novel constant region sequences having reduced Fcγ receptor-binding, while minimizing the generation of novel T-cell epitope peptides. As a result, the present inventors successfully discovered antibody constant regions with improved physicochemical properties (stability and homogeneity), immunogenicity, safety, and pharmacokinetics.

The invention discloses a Pichia pastoris indirect surface display system based on a TRAP protein scaffold, which is characterized in that Sed1p protein from saccharomyces cerevisiae is used as anchoring protein, and tetrapeptide repeat affinity protein TRAP is fixed on the anchoring protein on the surface of a Pichia pastoris cell to obtain the Pichia pastoris indirect surface display system based on the TRAP protein scaffold. The target protein with the carboxyl end fused with the peptide MEEVV or the peptide MRRVW is indirectly displayed on the surface of the pichia pastoris cell through specific binding with the tetrapeptide repeat affinity protein TRAP. The xylanase and the beta-xylosidase are indirectly displayed on the surface of the pichia pastoris cell by utilizing the surface display system, so that the pichia pastoris surface display system has the catalytic capabilities of the xylanase and the beta-xylosidase, can perform a synergistic effect to degrade the zelkova xylan, and has a good application prospect.

A multi-specific antibody contains at least one binding site for a cell specific antigen and at least one binding site for a tumor-reactive lymphocyte antigen and a multi-specific antibody including an IgG antibody or fragment thereof that binds to a first antigen; and at least one scFv antibody that binds to a second antigen that is different from the first antigen and is linked to a C terminus of at least one light chain or heavy chain of said IgG antibody or fragment. The multi-specific antibody reversibly binds to at least one of the cell specific antigen and tumor-reactive lymphocyte antigen or the first antigen and the second antigen with a greater affinity at an aberrant condition than at a normal physiological condition. Conjugates of the multi-specific antibodies and methods for generating the multi-specific antibody are also provided.

This invention discloses a lipopeptide HIV membrane fusion inhibitor and its pharmaceutical use. The lipopeptide of this invention is of formula I: X1-EMTWEEWEK KVEELEKKIEELLK-X2-X3-X4-X5; or formula II: X1-ELTWEEWEKKVEELEKKIEELLK-X6-X7-X4-X5; wherein, X1 is an amino-terminal protecting group; X2 is a polypeptide sequence (EAAAK)n, A[(EAAAK)n]A, or (EP)n, where n represents the number of repetitions; X3 is Lys, Cys, Dap, Orn, Dab, Dah, or absent; X4 is a lipophilic compound group used to modify the C-terminus; X5 is a carboxyl-terminal protecting group; X6 is a polypeptide sequence KAEEQQKKNE; and X7 is Lys, Cys, Dap, Orn, Dab, or Dah. The lipopeptide of this invention has higher antiviral activity.

The invention provides a whey protein isolate source antioxidant polypeptide, the amino acid sequence of the whey protein isolate source antioxidant polypeptide is amino terminal-LVYPFPGPIP-carboxyl terminal, and the whey protein isolate source antioxidant polypeptide can be developed into an antioxidant.

The present disclosure relates to bispecific binding proteins comprising, from the amino terminal to the carboxy terminal, (a) a first moiety, which is an anti-BAFF antibody or antigen binding fragment thereof, and (b) a second moiety, which is an anti-MASP2scFv or truncated TACI polypeptide. Furthermore, the invention relates to nucleic acid molecules encoding such bispecific binding proteins, as well as vectors and host cells comprising such nucleic acid molecules. The invention further relates to a method for producing said bispecific binding proteins and to the use of said bispecific binding proteins in the treatment of autoimmune diseases.

The present inventors succeeded in improving the antibody constant region to have increased stability under acid conditions, reduced heterogeneity originated from disulfide bonds in the hinge region, reduced heterogeneity originated from the H chain C terminus, and increased stability at high concentrations as well as in discovering novel constant region sequences having reduced Fcγ receptor-binding, while minimizing the generation of novel T-cell epitope peptides. As a result, the present inventors successfully discovered antibody constant regions with improved physicochemical properties (stability and homogeneity), immunogenicity, safety, and pharmacokinetics.

The invention discloses a method for preparing semeglutide by using a natural chemical ligation method, which comprises the following steps: (1) synthesizing semeglutide in two segments, namely an N-terminal segment with carboxyl-terminal hydrazide and a C-terminal segment with amino-terminal cysteine; (2) connecting the two fragments through a natural chemical connection method under a buffer salt condition; and (3) performing desulfurization treatment to convert Cys into target amino acid, and performing purification and freeze-drying after complete treatment. According to the method, the semeglutide is divided into the C-terminal polypeptide fragment and the N-terminal polypeptide fragment, the C-terminal polypeptide fragment and the N-terminal polypeptide fragment are connected through natural chemical connection reaction after being prepared respectively, then desulfurization treatment is conducted, the high-purity and high-yield semeglutide is finally obtained, the problem of difficult sequences is solved, the synthesis efficiency and purity of the semeglutide are remarkably improved, and the method is suitable for industrial production. The method is suitable for large-scale production.

The invention discloses a whey protein source peptide with hyaluronidase inhibitory activity. The whey protein source peptide is characterized in that the sequence of the whey protein source peptide is amino terminal-GGVSLPEW-carboxyl terminal. The peptide has the advantages of no toxicity, no sensitization and the like, has a remarkable inhibition effect on hyaluronidase, and can be used for developing functional foods or medicines with anti-allergic characteristics.

The invention provides a biosensor for detecting nitrate content as well as a preparation method and application thereof, and relates to the technical field of biology. The biosensor disclosed by the invention comprises a luciferase amino terminal fragment, a luciferase carboxyl terminal fragment and NasR protein, the luciferase amino terminal fragment and the luciferase carboxyl terminal fragment are two fragments of the same luciferase. The biosensor provided by the invention has high selectivity on nitrate, can specifically, stably, continuously and online observe the nitrate content in the whole plant for a long time, and overcomes the key problems of destructive sampling, limited spatial resolution, insufficient detection sensitivity and the like in the traditional method; and a real-time dynamic detection platform capable of monitoring the whole plant living body is provided for plant nitrogen metabolism research.

The application discloses a kind of MS2 virus-like particles based on capsid protein site-directed mutation and its preparation method and application, belong to molecular biological technique field.The amino acid of the beta sheet interface of capsid protein sequence, the amino acid of the interface when two capsid proteins molecules assemble, the carboxyl end site of capsid protein is subjected to site-directed mutation, obtain the mutant that can significantly improve the assembly efficiency and stability of capsid protein dimer.Utilize the mutant to construct MS2 virus-like particles, further by the design of mature enzyme and capsid protein expression element, control mature enzyme weak expression, capsid protein strong expression, to improve assembly efficiency.The application improves the assembly efficiency of MS2 virus by the above strategy, improves the proportion of wrapped RNA, enhances the stability of virus-like particle, greatly prolongs the stable storage time of RNA, improves the purity of wrapped RNA.

The invention discloses a whey protein source peptide with hyaluronidase inhibitory activity. The whey protein source peptide is characterized in that the sequence of the whey protein source peptide is amino terminal-GVSLPEW-carboxyl terminal. The peptide has the advantages of no toxicity, no sensitization and the like, has a remarkable inhibition effect on hyaluronidase, and can be used for developing functional foods or medicines with anti-allergic characteristics.

The application provides an mRNA vaccine and a preparation method and application thereof. Specifically, the application provides application of GMCSF as an immune adjuvant in preparation of an mRNA vaccine, and further provides an mRNA molecule, which encodes a GMCSF-antigen-FC1 fusion protein, wherein the GMCSF-antigen-FC1 fusion protein comprises, from an N terminus to a C terminus, an amino acid sequence of GMCSF, an amino acid sequence of an antigen and an amino acid sequence of FC1 in sequence, wherein the antigen is an antigen from a virus. The mRNA molecule of the application can be used for preparing a vaccine for preventing infection of novel coronavirus BA2 and BA5 mutant strains, and can induce a strong immune response.

The invention relates to a group of scorpion-derived antibacterial peptides capable of destroying cell membranes and application of the scorpion-derived antibacterial peptides. The polypeptides comprise a HeCT1 polypeptide, a HeCT2 polypeptide, a HeCT1-M polypeptide and a HeCT2-M polypeptide, wherein the sequence of the HeCT2 polypeptide is shown as SEQ ID NO.1, the sequence of the HeCT1-M polypeptide is shown as SEQ ID NO.2, and the sequence of the HeCT2-M polypeptide is shown as SEQ ID NO.3, and the sequence of the HeCT2-M polypeptide is shown as SEQ ID NO.4. The carboxyl terminals of the polypeptides are subjected to amidation (-NH2) modification. Furthermore, the polypeptide is an amphiphilic polypeptide, has a cation alpha-helical structure, has the hydrophobicity of 0.4-0.72 and the hydrophobic moment of 0.6-0.9, and has 1-7 net positive charges.

The present disclosure relates to a method for optimizing a virus membrane fusion inhibitor, abroad-spectrum anti-coronavirus lipopeptide and use thereof. The present disclosure provides compounds or pharmaceutically acceptable salts thereof or derivatives thereof, wherein the compounds are shown in formula (I) or formula (II), X1 is an amino-terminal protecting group; X2 is a polypeptide with an amino acid sequence of (EAAAK)n or A[(EAAAK)n]A; X3 is lysine or cysteine or 2,3-diaminopropionic acid or ornithine or 2,4-diaminobutyric acid or 2,7-diaminoheptonic acid; X4 is a lipophilic compound group modified on X3 or X4 is a lipophilic compound group modified on K in X2; X5 is a carboxyl-terminal protecting group.

The application discloses a mucosal immunity enhanced recombinant lactobacillus expressing PEDV S1 protein and a construction method and application thereof. The mucosal immunity enhanced recombinant lactobacillus contains a recombinant lactic acid bacteria expression vector expressing the PEDV S1 protein, wherein the PEDV S1 protein is fused with an M cell targeting peptide (Col) and a dendritic cell targeting peptide (6aa) at an amino acid end, and is fused with a mucosal immunity adjuvant (LTB) at a carboxyl end; and the connection sequence of each part is Col-6aa-S1-LTB. The mucosal immunity enhanced recombinant lactobacillus constructed by the application significantly improves the mucosal immunity response efficiency (including intestinal mucus SIgA and serum IgG levels) of the PEDV S1 antigen through the synergistic effect of the targeting peptide (DC / MC targeting peptide) and the adjuvant (LTB), and can significantly induce humoral immunity, cellular immunity and mucosal immunity response of pregnant animals and produce maternal antibodies, improves the intestinal SIgA level of newborn animals, and provides an effective technical means for the prevention and treatment of PED.

This invention relates to the field of biomedical technology, specifically to a stabilized and modified herpes zoster virus gE protein, its preparation method, and its applications. The stabilized and modified herpes zoster virus gE protein of this invention is obtained through cysteine ​​mutation modification and structural design optimization, and exhibits improved expression levels, thermal stability, and immunogenicity compared to recombinant varicella-zoster virus gE protein with only the removal of the carboxyl-terminal hydrophobic transmembrane region and intracellular tail.

The present invention revealed that translating an mRNA that encodes a peptide containing an unnatural amino acid in a translation system that contains a ribosome containing an engineered L31 protein can increase the amount of the translated peptide. Furthermore, the invention revealed that by using this ribosome, the relative amount of by-products can also be reduced. An engineered L31 protein of the present invention has an amino acid sequence with deletion of 6 or more amino acid residues from the C terminus in the amino acid sequence of the wild-type Escherichia coli L31 protein.

A cancer neoantigen-expressing cell membrane GRP94-targeting chimeric antigen receptor, comprising a signal peptide region, a cell membrane GRP94-targeting antigen binding domain, a hinge region, a transmembrane domain, and a signal transduction activation domain which are connected in sequence from the amino terminus to the carboxyl terminus, wherein the nucleotide sequence and amino acid sequence of the signal peptide region are as shown in SEQ ID No: 1 and SEQ ID No: 2 respectively; and the antigen binding domain is a portion of an antibody itself that targets cancer neoantigen-expressing cell membrane GRP94, or formed between portions of the antibody itself or between a portion thereof and an antibody region for another target. A novel chimeric antigen receptor (CAR)-engineered NK immune cell and a cancer drug can rapidly induce apoptosis in novel cancer cells having potentially cancer antigen-expressing cell membrane GRP94 protein, generate no toxic and side effects such as cytokine storms, and have off-the-shelf universal applicability, thereby providing a new choice for cell immunotherapy for cancers and also laying a foundation for accurate individualized treatment for cancer treatment.

This invention relates to a GFAP antigen, a GFAP antigen expression gene, a GFAP antigen expression vector, and their uses. The GFAP antigen consists of the GFAP protein and a polymerized protein motif at the C-terminus of the GFAP protein. This invention constructs a eukaryotic expression vector for the GFAP antigen and creatively introduces a polymerized fusion expression protein motif at the C-terminus of the GFAP protein, which can promote the protein phase transition of the GFAP protein in vivo. This invention discovers that adding a polymerized protein motif can transform the diffuse wild-type GFAP protein into a more dense aggregated structure, locally increasing the concentration of the GFAP antigen protein and causing the positive signal to exhibit a unique aggregation morphology, with the aggregation effect of the tetrameric GFAP-Tetramer plasmid being particularly significant. This invention introduces mCherry fluorescent protein on the basis of the tetramerization of the GFAP protein, enabling dual-fluorescence detection. Compared with existing immunofluorescence detection methods, the detection method provided by this invention further increases the detection sensitivity and specificity, making the interpretation of detection results more clear.

Provided is a novel production method with which a heteromultimeric protein such as a bispecific antibody can be produced. The production method of the present disclosure is a method for producing a heteromultimeric protein, and includes a complex formation step and a generation step. The complex formation step is a step of forming a first complex of two proteins by bringing the two proteins into contact with each other. In the complex formation step, the two proteins includes a first protein and a second protein. The first protein includes a first binding tag, a first cleavable domain, and a first domain in this order from the N terminus to the C terminus. The second protein includes a first binding partner capable of binding to the first binding tag, a second cleavable domain, and a second domain in this order from the N terminus to the C terminus.

The invention relates to the field of drug synthesis, and discloses a preparation method of semeglutide with a high fragment utilization rate, which comprises the following steps: taking amino acids from the first site to the sixteenth site of a semeglutide sequence as a fragment I, and taking amino acids from the 17th site to the 29th site of the semeglutide sequence as a fragment II; the 30th to 31st amino acids of the sequence of the semeglutide are used as a fragment III; a semeglutide product is prepared from the first fragment, the second fragment and the third fragment through a solid-liquid combination method, three fragments with C-terminal amino acids being Gly are preferably selected in the method, racemization impurities cannot be generated during condensation of the fragments, the synthesized fragments are high in purity and good in solubility, polypeptide fragment condensation reaction is easy to carry out, and the method is suitable for industrial production. The input amount of amino acid is only 1.5-2 times when the fragment is synthesized, the synthesized fragment does not need to be purified, the input amount of a carboxyl terminal fragment is only 0.95-1.05 times that of the amino acid fragment when the fragment is condensed, the fragment utilization rate is high, the cost is low, the unutilized fragment can be extracted and separated, and the post-treatment is simple.

The application discloses application of combination of CAR-T and CAR-M in preparation of antitumor drugs, wherein the CAR-T is a T cell modified by a chimeric antigen receptor, and the primary protein structure of the chimeric antigen receptor sequentially comprises a signal peptide, an NKG2D extracellular region, a hinge region, a transmembrane region, an intracellular costimulatory signal region and an intracellular signal region from an amino terminus to a carboxyl terminus; the CAR-M is a macrophage modified by a chimeric antigen receptor, and the primary protein structure of the chimeric antigen receptor sequentially comprises a signal peptide, an NKG2D extracellular region, a hinge region, a transmembrane region and an intracellular signal region from an amino terminus to a carboxyl terminus; and the NKG2D extracellular region is a human NKG2D extracellular domain, and the amino acid sequence is shown as SEQ ID NO. 2. The combination of the CAR-T and the CAR-M combines the ability of the CAR-M to improve a tumor microenvironment with the ability of the CAR-T to directly kill tumor cells, so that strong and efficient killing of tumor cells can be realized, and the curative effect is greatly improved.

This invention discloses an iron-catalyzed method for modifying unprotected glycine or N-terminal glycine peptides. Using the N-terminus of glycine as the modification site, unprotected glycine and the peptide are modified by heating with 2-benzoylpyridine in the presence of an iron catalyst and additives to form a fluorescent nitrogen-containing aromatic heterocycle, thus completing the modification of unprotected glycine or unprotected N-terminal glycine peptides. This invention overcomes the deficiency of requiring carboxyl-terminal protection when labeling unprotected glycine or glycine-containing peptides. The provided modification method eliminates the need for protection followed by deprotection, is simple, has a short reaction time, and high yield. As a novel N-terminal glycine peptide modification and labeling technology, this invention can be effectively used for the modification of unprotected N-terminal glycine peptides, establishing a theoretical foundation for improving peptide drug bioavailability, developing new targeted drugs, and peptide labeling and tracking.

The invention provides undecapeptide with antibacterial activity. The undecapeptide is characterized in that the amino acid sequence of the undecapeptide is amino terminal-AKKLLKWVKKK-carboxyl terminal. The peptide disclosed by the invention not only can effectively inhibit the growth of various bacteria, shows excellent antibacterial activity, but also has a certain antioxidant effect, can relieve the damage of oxidative stress to cells, and can be used for trying to develop anti-infection drugs, food preservatives or functional skin care products.