# US 2010/0075897 A1 · Method for sustainedly releasing bioactive peptides and application thereof

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- Number: US 2010/0075897 A1
- Document ID: US20100075897A1
- Status: Published application
- Kind: A1
- Application number: 12/236,343
- Filed: 2008-09-23
- Published: 2010-03-25
- Earliest claimed: 2008-09-23
- Assignees: Jinan University
- Inventors: Hongjian Li; Zhengding Su; Tianhong Zhou
- Web page: https://patentgrep.com/patent/US20100075897A1

## CPC

- A61K 38/26: Glucagons
- A61K 38/1761: {Apoptosis related proteins, e.g. Apoptotic protease-activating factor-1 (APAF-1), Bax, Bax-inhibitory protein(s)(BI; bax-I), Myeloid cell leukemia associated protein (MCL-1), Inhibitor of apoptosis [IAP] or Bcl-2}
- A61K 38/23: Calcitonins
- A61K 47/65: Peptidic linkers, binders or spacers, e.g. peptidic enzyme-labile linkers
- A61P 35/00: Antineoplastic agents
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)
- A61P: SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS

## Abstract

The present invention provides a method for sustainedly releasing bioactive peptide, comprising a bioactive peptide conjugated to a serum albumin binding peptide through a molecular linker so as to form a fusion polypeptide, in which the molecular linker is sensitive to plasma environment; and transferring the fusion polypeptide to a host, whereby plasma proteinase or alkaline pH of blood in the host can cleave the molecular linker to release the bioactive peptide therein. The fusion polypeptide is sensitive to plasma environment and the sustained release of bioactive peptide ensures the activity of released peptide, resulting in an increased circulation half-life in the host. The present invention also provides a method for using the fusion polypeptide drug as described above to treat human type 2 diabetes, human osteoporosis or cancer.

## Claims

### Claim 1

A method for sustainedly releasing bioactive peptide from a fusion polypeptide, comprising
providing a fusion polypeptide including a bioactive peptide conjugated to a serum albumin binding peptide through a cleavable molecular linker, wherein the molecular linker is sensitive to plasma environment and serves as a switch to sustainedly release bioactive peptide therein; and
administrating a host the fusion polypeptide, whereby plasma proteinases or mild alkalinity of blood in the host can catalytically cleave the molecular linker to release the bioactive peptide therein.

### Claim 2 (depends on 1)

The method of claim 1, wherein the serum albumin binding peptide has an amino acid sequence as following formula (I):
(I)
Xaa1-Xaa2-Xaa3-Xaa4-Xaa5-Xaa6-Xaa7-Xaa8-Xaa9-
Xaa10-Xaa11-Xaa12,
wherein
Xaa1 is leucine;
Xaa2 is proline;
Xaa3 is any amino acid except cysteine;
Xaa4 is any amino acid;
Xaa5 is any amino acid;
Xaa6 is a positively charged amino acid;
Xaa7 is a hydrophobic amino acid;
Xaa8 is a positively charged amino acid;
Xaa9 is any amino acid except cysteine;
Xaa10 is a hydrophobic amino acid;
Xaa11 is proline; and
Xaa12 is any amino acid.

### Claim 3 (depends on 2)

The method of claim 2, wherein the serum albumin binding peptide is Leu-Pro-Trp-His-Leu-Lys-Tyr-Arg-Glu-Pro-Pro-Arg or Leu-Pro-His-Ser-His-Arg-Ala-His-Ser-Leu-Pro-Pro.

### Claim 4 (depends on 1)

The method of claim 1, wherein the molecular linker has an amino acid sequence of thrombin recognition site, wherein said amino acid sequence comprises an amino acid sequence of the following formula (II):
Xaaj-Xaak-Xaai-Arg-Xaam-Xaan,
(II)
wherein
Xaaj is a hydrophobic amino acid or peptidyl bond;
Xaak is a hydrophobic amino acid or peptidyl bond;
Xaai is proline or valine;
Xaam is a non-acidic amino acid or peptidyl bond; and
Xaan is a non-acidic amino acid or peptidyl bond.

### Claim 5 (depends on 4)

The method of claim 4, wherein the molecular linker is Phe-Asn-Pro-Arg-Gly-Ala, Phe-Asn-Pro-Arg-Gly-Ser, Phe-Asn-Pro-Arg-Gly-Pro, Phe-Asn-Pro-Arg-Pro-Pro or Phe-Asn-Pro-Arg-Pro-Ala.

### Claim 6 (depends on 1)

The method of claim 1, wherein the molecular linker is a disulfide bond.

### Claim 7 (depends on 1)

The method of claim 1, wherein the serum albumin binding peptide is Ser-Leu-Phe-Arg-His-Gln-His-Ala-Thr-Pro-Gln-Ile, Ser-Leu-Leu-His-Trp-Thr-His-Lys-Ile-Pro-Ala-Leu or Lys-Tyr-Asn-His-Ser-Hlis-Lys-Tyr-Trp-Gln-Arg-Pro.

### Claim 8 (depends on 1)

The method of claim 1, wherein the bioactive peptide is human glucagon-like peptide-1, calcitonin or any one of peptides binding to Bcl-2 family apoptotic proteins.

### Claim 9 (depends on 8)

The method of claim 8, wherein the peptide binding to Bcl-2 family apoptotic protein is a BH3 peptide derived from Bax protein.

### Claim 10 (depends on 1)

A method for using the fusion polypeptide according to claim 1 to treat human type 2 diabetes.

### Claim 11 (depends on 1)

A method for using the fusion polypeptide according to claim 1 to treat human osteoporosis.

### Claim 12 (depends on 1)

A method for using the fusion polypeptide according to claim 1 to treat human cancer.