New peptide

Abstract

To provide a new peptide that has superior intracellular incorporating performance and selectivity, and can function as an unprecedented intracellular transport carrier.SOLUTION: A new peptide composed of SZEXSRLSZEXSRLSZEXSRL. Herein, G denotes N-acetylgalactosamine (GalNAc), galactose (Gal), sialic acid (Sia), mannose (Man), mannosamine, glucose (Glc), or N-acetylglucosamine (GlcNAc), L denotes a linker and is shown by -L1-L2-L3- from ones closer to G, where L1 denotes C1 to C10 alkyl, -(OCH2CH2)n-(n denotes 1 to 5), C2 to C10 alkoxy, C1 to C10 aryl and amide, L2 denotes triazole, phosphodiester, thio-phosphodiester, sulfate, amide, heteroaryl, and ester, and L3 denotes C1 to C10 alkyl, C2 to C10 alkoxy, C1 to C10 aryl, amide, and C2 to C10 alkyldithio.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a novel peptide, and more particularly to a novel peptide that can be used as a carrier capable of transporting a cargo molecule into a cell. [Background technology]

[0002] Cells are separated from the outside world by a cell membrane that is impermeable to hydrophilic bioactive substances such as proteins and nucleic acids. The lack of a method for delivering these hydrophilic bioactive substances into cells has been an obstacle to the clinical use of many hydrophilic bioactive substances that act within the cell. Several techniques have been reported for delivering such cell-impermeable hydrophilic bioactive substances into cells. The most common method is to use lipids to impart hydrophobicity to hydrophilic bioactive substances, which can improve their ability to pass through the cell membrane. Techniques for improving permeability using peptide ligands have also been reported.

[0003] Peptide ligands that have the property of migrating from outside the cell to inside the cell without destroying the cell membrane are called cell membrane penetrating peptides (CPPs). Cell membrane penetrating peptides (CPPs) are used as carriers (DDS carrier peptides) that can transport highly hydrophilic drugs and polymeric drugs (cargo molecules) such as proteins and nucleic acids into cells. Well-known examples include oligoarginine, which is a series of arginines, the peptide Tat derived from the HIV-1 virus (Patent Document 1), and penetratin, a peptide derived from Drosophila melanogaster (Patent Document 2). In addition to these, various other peptides have been reported, including those characterized by simple basicity, those characterized by amphiphilicity of the primary or secondary structure of the peptide, and those with unclear mechanisms. In addition to their own intracellular migration, as mentioned above, research is being actively conducted on the use of these peptides to deliver hydrophilic physiologically active substances such as genes linked to them as vehicles into the cell.

[0004] Many CPPs are composed of sequences based on cationic amino acids including Arg and Lys. However, there are still issues to be overcome, such as cytotoxicity, hepatotoxicity, and insufficient cell and tissue selectivity. Although they have a proven track record as research reagents, few are used in clinical applications. Various attempts are being made to find sequences that can be transported into cells more efficiently for each application.

[0005] On the other hand, drug discovery tools that utilize ligands of sugar receptors expressed on the cell membrane surface as cell- and tissue-selective DDS carriers have been developed. For example, there is an example in which the asialoglycoprotein receptor (ASGPR) expressed in hepatocytes is targeted and its ligand, N-acetylgalactosamine (GalNAc), is used (Non-Patent Documents 1 and 2).

[0006] Tri-GalNAc, which has three GalNAc molecules attached to a flexible linker, is used as an intracellular delivery tool for antisense nucleic acids. For example, Vutrisiran, which has trivalent GalNAc attached, can be administered subcutaneously, and has a proven track record as a nucleic acid drug (Non-Patent Document 3).

[0007] Thus, GalNAc is used as a tissue- and cell-selective DDS carrier molecule; however, detailed research has not been conducted on its functionality and appropriate structure as a carrier. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 10-33186 [Patent Document 2] Special Publication No. 2002-530059 [Non-patent literature]

[0009] [Non-Patent Document 1] Jeon, JY, et al., Pharm. Res., 39, 1749-1759(2022) [Non-Patent Document 2] Zimmermann, TS, et al., Mol. Ther., 25, 71-78(2017) [Non-Patent Document 3] Adams, D., et al., Amyloid, (2022)doi: 10.1080 / 13506129.2022.2091985. Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention has been made in consideration of such problems, and aims to provide a novel peptide that has superior cellular uptake performance and selectivity and can function as an unprecedented intracellular transport carrier. [Means for solving the problem]

[0011] The novel peptide according to the present invention is composed of SZEXSRLSZEXSRLSZEXSRL, where X is the following structural formula (1), Z is the following structural formula (2), G is N-acetylgalactosamine (GalNAc), galactose (Gal), sialic acid (Sia), mannose (Man), mannosamine, glucose (Glc), N-acetylglucosamine (GlcNAc), fucose, or xylose, and L is a linker, starting from the side closest to G, -L. 1 -L 2- L 3 -, where L 1 is C1-C10 alkyl, -(OCH 2 CH 2 ) n -(n is 1 to 5), C2 to C10 alkoxy, C1 to C10 aryl, amide, C2 to C10 alkyldithio, ether, thioether, ester, oligonucleotide, oligopeptide, thiopropionate, disulfide, or absent, L 2is a triazole, phosphodiester, thiophosphodiester, sulfate, amide, heteroaryl, ester, ether, thioether, disulfide, thiopropionate, acetal, or glycol; L 3 is C1 to C10 alkyl, C2 to C10 alkoxy, C1 to C10 aryl, amide, C2 to C10 alkyldithio, ether, thioether, ester, oligonucleotide, oligopeptide, thiopropionate, disulfide, or absent.

[0012] [ka]

[0013] [ka] Effect of the Invention

[0014] The novel peptide of the present invention has superior cellular uptake performance and selectivity, and can function as an intracellular transport carrier that has not been previously available. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 shows the structure of novel peptide 3-5 according to the present invention. [Diagram 2] FIG. 1 shows the structure of the novel peptide 3-5SBR according to the present invention. [Diagram 3] FIG. 1 shows the CD spectra of peptide 3-5 and peptide 3-5SBR. [Figure 4] FIG. 1 shows the uptake of each peptide into HepG2 cells. [Diagram 5] FIG. 1 shows the uptake of each peptide into HepG2 cells and HeLa cells. [Figure 6] FIG. 1 is a diagram illustrating the binding of the N-terminal biotin-modified peptide 3-5SBR-biotin to streptavidin. [Figure 7] FIG. 1 shows the uptake of each peptide into HepG2 cells and HeLa cells. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described in detail with reference to the attached drawings. However, the embodiment is intended to facilitate understanding of the principles of the present invention, and the scope of the present invention is not limited to the embodiment described below. Other embodiments in which a person skilled in the art appropriately replaces the configuration of the embodiment described below are also included in the scope of the present invention.

[0017] The novel peptide according to the present invention is composed of SZEXSRLSZEXSRLSZEXSRL, where X is the following structural formula (1), Z is the following structural formula (2), G is N-acetylgalactosamine (GalNAc), galactose (Gal), sialic acid (Sia), mannose (Man), mannosamine, glucose (Glc), N-acetylglucosamine (GlcNAc), fucose, or xylose, and L is a linker, starting from the side closest to G, -L. 1 -L 2- L 3 -, where L 1 is C1-C10 alkyl, -(OCH 2 CH 2 ) n -(n is 1 to 5), C2 to C10 alkoxy, C1 to C10 aryl, amide, C2 to C10 alkyldithio, ether, thioether, ester, oligonucleotide, oligopeptide, thiopropionate, disulfide, or absent, L 2 is a triazole, phosphodiester, thiophosphodiester, sulfate, amide, heteroaryl, ester, ether, thioether, disulfide, thiopropionate, acetal, or glycol; L 3is C1 to C10 alkyl, C2 to C10 alkoxy, C1 to C10 aryl, amide, C2 to C10 alkyldithio, ether, thioether, ester, oligonucleotide, oligopeptide, thiopropionate, disulfide, or absent.

[0018] [ka]

[0019] [ka]

[0020] The novel peptide according to the present invention preferably consists of SZEXSRLSZEXSRLSZEXSRL, where X is the following structural formula (1) and Z is the following structural formula (3).

[0021] [ka]

[0022] [ka]

[0023] The novel peptide of the present invention is a peptide compound carrying three GalNAc molecules, and has a controlled three-dimensional structure, and furthermore, the helix is ​​highly stabilized by X. Therefore, the peptide has superior intracellular uptake performance and selectivity compared to conventional peptides.

[0024] The novel peptide according to the present invention is composed of LZSXSSLLZSXSSLLZSXSSL, where X is the following structural formula (1), Z is the following structural formula (2), G is N-acetylgalactosamine (GalNAc), galactose (Gal), sialic acid (Sia), mannose (Man), mannosamine, glucose (Glc), N-acetylglucosamine (GlcNAc), fucose, or xylose, and L is a linker, with -L being the first one closer to G, and -L being the second one closer to G. 1 -L 2- L 3 -, where L 1 is C1-C10 alkyl, -(OCH 2 CH 2 ) n -(n is 1 to 5), C2 to C10 alkoxy, C1 to C10 aryl, amide, C2 to C10 alkyldithio, ether, thioether, ester, oligonucleotide, oligopeptide, thiopropionate, disulfide, or absent, L 2 is a triazole, phosphodiester, thiophosphodiester, sulfate, amide, heteroaryl, ester, ether, thioether, disulfide, thiopropionate, acetal, or glycol; L 3 is C1 to C10 alkyl, C2 to C10 alkoxy, C1 to C10 aryl, amide, C2 to C10 alkyldithio, ether, thioether, ester, oligonucleotide, oligopeptide, thiopropionate, disulfide, or absent.

[0025] [ka]

[0026] [ka]

[0027] The novel peptide according to the present invention preferably consists of LZSXSSLLZSXSSLLZSXSSL, where X is the following structural formula (1) and Z is the following structural formula (3).

[0028] [ka]

[0029] [ka]

[0030] The novel peptide of the present invention is a peptide compound carrying three GalNAc molecules, has a controlled three-dimensional structure, and has superior intracellular uptake properties compared to conventional peptides.

[0031] The novel peptide according to the present invention can be labeled with a fluorescent dye and can be described as FB-SZEXSRLSZEXSRLSZEXSRL or FB-LZSXSSLLZSXSSLLZSXSSL.

[0032] Here, B is the following structural formula (4).

[0033] [ka]

[0034] F represents a fluorescent dye, and examples thereof include, but are not limited to, FITC, Rhodamine 110, GFP, TAMRA, and Atto 633.

[0035] The N-terminus or C-terminus of the novel peptide of the present invention may be chemically modified. For example, the C-terminus may be -COOH or -COO - or amidation (-CONH 2 ), alkylamidated (-CONHR), or esterified (-COOR), and the N-terminus is -NH 2 or -NH 3 +or may be acylated (-NHCOR), where R represents a C1-6 alkyl group.

[0036] The novel peptide according to the present invention may be in the form of a salt. Such salts are preferably pharma- ceutically acceptable. Examples of counter cations constituting such salts include metal ions and ammonium ions (NH 4 + ), organic base ions, and basic amino acid ions, and counter anions include, for example, inorganic acid ions, organic acid ions, and acidic amino acid ions. Metal ions constituting metal salts include, for example, alkali metal ions such as lithium ion, sodium ion, and potassium ion; alkaline earth metal ions such as calcium ion and barium ion; and magnesium ion. Organic bases constituting organic base salts include, for example, trimethylamine, triethylamine, pyridine, picoline, 2,6-lutidine, ethanolamine, diethanolamine, triethanolamine, cyclohexylamine, dicyclohexylamine, and N,N'-dibenzylethylenediamine. Basic amino acids constituting basic amino acid salts include lysine, arginine, and histidine. Inorganic acids constituting inorganic acid salts include, for example, hydrochloric acid, hydrobromic acid, nitric acid, sulfuric acid, and phosphoric acid. Examples of organic acids constituting the organic acid salts include formic acid, acetic acid, trifluoroacetic acid, phthalic acid, fumaric acid, oxalic acid, tartaric acid, maleic acid, citric acid, succinic acid, malic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, etc. Examples of acidic amino acids constituting the acidic amino acid salts include aspartic acid and glutamic acid.

[0037] The novel peptide according to the present invention can be produced by a conventional method, and is not particularly limited, for example, by solid phase synthesis. Specifically, after the amino acid sequence of a cell membrane-penetrating peptide is designed, a C-terminal amino acid residue in which the amino group and, if necessary, the side chain reactive group are protected is bound to a solid resin, and then deprotection of the amino group and binding of the next amino acid residue are repeated, and finally, the peptide is cleaved from the solid resin and deprotected.

[0038] The novel peptide of the present invention can be used as a cell membrane permeable peptide (CPP), and is delivered into cells by penetrating the cell membrane, so that it is considered that side effects are relatively few and the action and effect of the physiologically active peptide is effectively exerted. Since the cell membrane permeable peptide of the present invention is a peptide, it is preferable to administer it by injection when it is used as a medicine. When the novel peptide of the present invention is used as a medicine, water is preferable as a solvent for the injection. Furthermore, depending on the water solubility of the peptide of the present invention, it may contain a water-miscible organic solvent such as ethanol, ethylene glycol, propylene glycol, or polyethylene glycol. In addition, it may contain additives such as salts such as sodium chloride, buffer components, and preservatives. When the novel peptide of the present invention is used as a medicine, the dosage may be appropriately adjusted depending on the severity, age, sex, weight, symptoms, etc. of the patient to be administered. For example, the dosage can be adjusted within a range of 0.001 mg / kg / day or more and 100 mg / kg / day or less, preferably 0.005 mg / kg / day or more and 50 mg / kg / day or less. EXAMPLES

[0039] (1) Peptide synthesis The synthesis of FITC-B-LZSXSSLLZSXSSLLZSXSSL (peptide 3-5) (SEQ ID NO:11) was as follows.

[0040] First, GalNAc-≡ was synthesized according to the following scheme (synthesis of GalNAc derivative).

[0041] [ka]

[0042] Next, 50 μmol of Protide LL Rink-amide resin (CEM, MA) was suspended in a 1 / 1 DMF / DCM solution. Using a Liberty Blue Automatic Synthesizer (CEM), the peptide was extended on a 50 μmol scale under microwave irradiation. 4 mL of a 95 / 2.5 / 2.5 mixture of TFA / water / TIPS was added, and the peptide was cleaved from the solid support by heating at 40°C for 30 minutes. TFA was evaporated under a nitrogen stream, and ether was added to the residue. After centrifugation, the supernatant was removed, and the crude peptide was purified by HPLC (60-80% in 20 min then 80-100% in 30 min MeCN / H 2 As shown in the scheme below, the purified peptide was lyophilized, and then GalNAc-≡ (9 equivalents) and 200 μL of DMSO were added, and CuSO dissolved in water was added. 4 5H 2 A mixture of 200 μL of O (2 equivalents) and sodium ascorbate (2 equivalents) was added and stirred overnight (synthesis of GalNAc-loaded peptide by reaction of GalNAc derivative with peptide).

[0043] [ka]

[0044] FITC (3 equivalents) and 10 μL of DIPEA were added and the mixture was stirred for another day. The reaction mixture was purified by HPLC (50-90% in 40 min MeCN / H 2 The peptides were then lyophilized in 0.2% TFA (O with 0.1% TFA) and their structures were identified by LC-TOFMS (Figure 1).

[0045] In addition, the other peptides 1-1 to 1-6 and 3-1 to 3-8 shown below were also synthesized and purified by the same route. FITC-B-LZSXSSLLSSXSSLLSSXSSL (peptide 1-1) (SEQ ID NO: 1) FITC-B-LSSXSZLLSSXSSLLSSXSSL (peptide 1-2) (SEQ ID NO: 2) FITC-B-LSSXSSLLZ SXS SLLSSXSSL (peptide 1-3) (SEQ ID NO: 3) FITC-B-LSSXSSLLSSXSZLLSSXSSL (Peptide 1-4) (SEQ ID NO: 4) FITC-B-LSSXSSLLSSXSSLLZSXSSL (peptide 1-5) (SEQ ID NO: 5) FITC-B-LSSXSSLLSSXSSLLSSXSZL (Peptide 1-6) (SEQ ID NO: 6) FITC-B-LZSXSZLLZSXSSLLSSXSSL (Peptide 3-1) (SEQ ID NO: 7) FITC-B-LSSXSZLLZSXSZLLSSXSSL (peptide 3-2) (SEQ ID NO: 8) FITC-B-LSSXSSLLZSXSZLLZSXSSL (peptide 3-3) (SEQ ID NO: 9) FITC-BL SSXSSLLSSXSZLLZSXSZL (Peptide 3-4) (SEQ ID NO: 10) FITC-B-LSSXSZLLSSXSZLLSSXSZL (Peptide 3-6) (SEQ ID NO: 12) FITC-B-SLZXSSLZLSXSSLLZLXSSS (Peptide 3-7) (SEQ ID NO: 13) FITC-B-SLSXZSLSLSXSZLLSLXSSZ (Peptide 3-8) (SEQ ID NO: 14)

[0046] (2) Synthesis of peptides with reduced hydrophobicity FITC-B-SZEXSRLSZEXSRLSZEXSRL (peptide 3-5SBR) (SEQ ID NO: 15), which has lower hydrophobicity than FITC-B-LZSXSSLLZSXSSLLZSXSSL (peptide 3-5), was synthesized as follows. Peptide 3-5 was highly hydrophobic and had low water solubility, but peptide 3-5SBR is a peptide in which hydrophilic E and R have been introduced into peptide 3-5.

[0047] 50 μmol of Protide LL Rink-amide resin (CEM) was suspended in a 1 / 1 DMF / DCM solution. Using a Liberty Blue Automatic Synthesizer (CEM), peptides were elongated on a 50 μmol scale under microwave irradiation. FITC (2 equivalents) and DIPEA (4 equivalents) were added and the mixture was shaken in DMF for 2 hours to introduce FITC. After the reaction, the mixture was washed twice with DMF and DCM. 4 mL of a 95 / 2.5 / 2.5 mixture of TFA / water / TIPS was added and heated at 40°C for 45 minutes to cleave the peptide from the solid support. TFA was evaporated with a nitrogen stream, and ether was added to the residue. After centrifugation, the supernatant was removed and the crude peptide was purified by HPLC (20-60% in 40min MeCN / H 2 After lyophilization of the purified peptide, GalNAc-≡ (6 equivalents) and 200 μL of DMSO were added, and CuSO dissolved in water was added. 4 5H 2 A mixture of 100 μL of 2H2O (2 equivalents) and sodium ascorbate (2 equivalents) was added and stirred overnight. The reaction mixture was purified by HPLC (20-60% in 40 min MeCN / H 2 The peptide was lyophilized in 0.05% TFA (O with 0.1% TFA) and its structure was identified by LC-TOFMS (Figure 2). Peptide 3-5SBR stabilized the helix by X.

[0048] (3) CD spectrum measurement of peptides CD spectra were measured for peptide 3-5 and peptide 3-5SBR under the following conditions: water / acetonitrile (1 / 1, 3-5), 20 mM phosphate buffer (pH = 7.4, 3-5SBR), and peptide concentration of 100 μM.

[0049] Fig. 3 shows the CD spectra of peptide 3-5 and peptide 3-5SBR, respectively. As shown in Fig. 3, each peptide was found to have a stable α-helical structure.

[0050] (4) HepG2 cell uptake test of each peptide N-acetylgalactosamine (GalNAc) is a ligand for the asialoglycoprotein receptor (ASGPR). Taking advantage of the fact that HepG2 cells express ASGPR, we examined the degree of uptake of each peptide into HepG2 cells.

[0051] Since the N-terminus of each peptide was modified with a fluorescent molecule (FITC), the uptake into HepG2 cells was calculated from the intracellular fluorescence intensity using a flow cytometer.

[0052] Figure 4 shows the uptake of each peptide into HepG2 cells. As shown in Figure 4, for example, peptides 3-5 showed superior uptake compared to the conventional TriGalNAc.

[0053] (5) Intracellular uptake test of each peptide in HepG2 and HeLa cells Next, the cellular uptake of peptide 3-5 and peptide 3-5SBR was examined. ASGPR-expressing HepG2 cells and non-ASGPR-expressing HeLa cells were used. Since the N-terminus of each peptide was modified with a fluorescent molecule (FITC), the cellular uptake was calculated from the intracellular fluorescence intensity using a flow cytometer.

[0054] FIG. 5 shows the uptake of each peptide into HepG2 cells and HeLa cells. The left side of FIG. 5 shows the uptake into HeLa cells, and the right side of FIG. 5 shows the uptake into HepG2 cells. As shown on the right side of FIG. 5, both peptide 3-5 and peptide 3-5SBR showed uptake into HepG2 cells. On the other hand, as shown on the left side of FIG. 5, the uptake of peptide 3-5SBR into HeLa cells was suppressed compared to peptide 3-5. Thus, both peptide 3-5 and peptide 3-5SBR showed excellent uptake into HepG2 cells, and 3-5SBR had superior cellular uptake selectivity to peptide 3-5. Note that Tat is FITC-B-YGRKKRRQRR.

[0055] (6) Streptavidin intracellular transport test of each peptide Streptavidin is a biotin-binding protein. As shown in Figure 6, the peptide 3-5SBR-biotin, which has a biotin-modified N-terminus, binds to streptavidin. When 3-5SBR-biotin is taken up into a cell, streptavidin is also taken up into the cell.

[0056] The synthesis protocol for 3-5-biotin was as follows.

[0057] 50 μmol of Protide LL Rink-amide resin (CEM) was suspended in a 1 / 1 DMF / DCM solution. Using a Liberty Blue Automatic Synthesizer (CEM), peptides were elongated on a 50 μmol scale under microwave irradiation. Biotin-PEG6-acid (4 equivalents), COMU (4 equivalents), and DIPEA (8 equivalents) were added and the mixture was shaken in DMF for 2 hours to introduce biotin. After the reaction, the mixture was washed twice with DMF and DCM. 4 mL of a 95 / 2.5 / 2.5 mixture of TFA / water / TIPS was added and heated at 40°C for 30 minutes to cleave the peptide from the solid support. TFA was evaporated with a nitrogen stream, and ether was added to the residue. After centrifugation, the supernatant was removed and the crude peptide was purified by HPLC (60-100% in 40min MeCN / H 2 After lyophilization of the purified peptide, GalNAc-≡ (9 equivalents) and 200 μL of DMSO were added, and CuSO dissolved in water was added. 4 5H 2 A mixture of 200 μL of 2H2O (2 equivalents) and sodium ascorbate (2 equivalents) was added and stirred. The reaction mixture was purified by HPLC (50-90% in 40 min MeCN / H 2 O with 0.1% TFA) and the peptide was lyophilized.

[0058] The synthesis protocol for 3-5SBR-biotin was as follows.

[0059] 50 μmol of Protide LL Rink-amide resin (CEM) was suspended in a 1 / 1 DMF / DCM solution. Using a Liberty Blue Automatic Synthesizer (CEM), peptides were elongated on a 50 μmol scale under microwave irradiation. Biotin-PEG6-acid (4 equivalents), COMU (4 equivalents), and DIPEA (8 equivalents) were added and shaken in DMF for 2 hours to introduce biotin. After the reaction, the mixture was washed twice with DMF and DCM. 4 mL of a 95 / 2.5 / 2.5 mixture of TFA / water / TIPS was added and heated at 40°C for 45 minutes to cleave the peptide from the solid support. TFA was evaporated with a nitrogen stream, and ether was added to the residue. After centrifugation, the supernatant was removed and the crude peptide was purified by HPLC (20-60% with 40min MeCN / H 2 After lyophilization of the purified peptide, GalNAc-≡ (6 equivalents) and 200 μL of DMSO were added, and CuSO dissolved in water was added. 4 5H 2 A mixture of 100 μL of 2H2O (2 equivalents) and sodium ascorbate (2 equivalents) was added and stirred overnight. The reaction mixture was purified by HPLC (20-60% in 40 min MeCN / H 2 O with 0.1% TFA) and the peptide was lyophilized.

[0060] The intracellular transport of streptavidin was examined using the peptides 3-5SBR-biotin, N-terminally modified with biotin, and 3-5-biotin, N-terminally modified with biotin, in HepG2 cells, which express ASGPR, and HeLa cells, which do not express ASGPR.

[0061] FIG. 7 shows the uptake of each peptide into HepG2 cells and HeLa cells. The left side of FIG. 7 shows the uptake into HepG2 cells, and the right side of FIG. 7 shows the uptake into HeLa cells. As shown in the left side of FIG. 7, both 3-5-biotin and 3-5SBR-biotin showed intracellular transport of streptavidin into HepG2 cells. On the other hand, as shown in the right side of FIG. 7, the intracellular transport of streptavidin into HeLa cells was significantly suppressed by 3-5SBR-biotin compared to 3-5-biotin. Thus, both 3-5-biotin and 3-5SBR-biotin showed excellent intracellular transport, and 33-5SBR-biotin had superior selectivity for intracellular transport compared to 3-5-biotin. [Industrial Applicability]

[0062] It can be used as a drug discovery technology for drug delivery systems, etc.

Claims

1. A novel peptide consisting of SZEXSRLSZEXSRLSZEXSRL (wherein X is the following structural formula (1), Z is the following structural formula (2), G is N-acetylgalactosamine (GalNAc), galactose (Gal), sialic acid (Sia), mannose (Man), mannosamine, glucose (Glc), N-acetylglucosamine (GlcNAc), fucose, or xylose, and L is a linker, starting from the side closest to G, -L. 1 -L 2- L 3 -, where L 1 is C1 to C10 alkyl, -(OCH 2 CH 2 ) n -(n is 1 to 5), C2 to C10 alkoxy, C1 to C10 aryl, amide, C2 to C10 alkyldithio, ether, thioether, ester, oligonucleotide, oligopeptide, thiopropionate, disulfide, or absent; L 2 is a triazole, phosphodiester, thiophosphodiester, sulfate, amide, heteroaryl, ester, ether, thioether, disulfide, thiopropionate, acetal, or glycol; L 3 is C1-C10 alkyl, C2-C10 alkoxy, C1-C10 aryl, amide, C2-C10 alkyldithio, ether, thioether, ester, oligonucleotide, oligopeptide, thiopropionate, disulfide, or absent. 【Chemistry 1】 【Chemistry 2】

2. The novel peptide according to claim 1, which is composed of SZEXSRLSZEXSRLSZEXSRL (wherein X is the following structural formula (1) and Z is the following structural formula (3)). 【Chemistry 3】 【Chemistry 4】

3. A novel peptide consisting of LZSXSSLLZSXSSLLZSXSSL (wherein X is the following structural formula (1), Z is the following structural formula (2), G is N-acetylgalactosamine (GalNAc), galactose (Gal), sialic acid (Sia), mannose (Man), mannosamine, glucose (Glc), N-acetylglucosamine (GlcNAc), fucose, or xylose, and L is a linker, with -L being the most proximal end of G. 1 -L 2- L 3 -, where L 1 is C1 to C10 alkyl, -(OCH 2 CH 2 ) n -(n is 1 to 5), C2 to C10 alkoxy, C1 to C10 aryl, amide, C2 to C10 alkyldithio, ether, thioether, ester, oligonucleotide, oligopeptide, thiopropionate, disulfide, or absent; L 2 is a triazole, phosphodiester, thiophosphodiester, sulfate, amide, heteroaryl, ester, ether, thioether, disulfide, thiopropionate, acetal, or glycol; L 3 is C1-C10 alkyl, C2-C10 alkoxy, C1-C10 aryl, amide, C2-C10 alkyldithio, ether, thioether, ester, oligonucleotide, oligopeptide, thiopropionate, disulfide, or absent. 【Chemistry 5】 【Chemistry 6】

4. The novel peptide according to claim 3, consisting of LZSXSSLLZSXSSLLZSXSSL (wherein X is the following structural formula (1) and Z is the following structural formula (3)). 【Chemistry 7】 【Chemistry 8】

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