Method for producing type IV collagen

Abstract

An object of the invention is to provide type IV collagen without contamination by other proteins and without degradation or denaturation. The present invention provides a type IV collagen which is derived and extracted from lens capsules without the use of an enzyme and has a minimum molecular weight of 160 to 180 kDa measured by SDS-PAGE under reduced conditions.

Description

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows the results of SDS-PAGE analysis of type IV collagen obtained in Example 1 and in Comparative Example 1. In the left diagram, the left lane indicates type IV collagen obtained from porcine eyeballs and the right lane indicates type IV collagen obtained from bovine eyeballs.

Claims

1. A type IV collagen which is derived and extracted from lens capsules without the use of an enzyme and has a minimum molecular weight of 160 to 180 kDa measured by SDS-PAGE under reduced conditions.

2. The type IV collagen of claim 1 which has intermolecular interactive domains at one of or both ends of a polypeptide chain.

3. The type IV collagen of claim 1 which has Gly-Xaa-Xbb (wherein Xaa and Xbb each independently represent any amino acid residue) repeats in the polypeptide chain molecule.

4. A method for producing the type IV collagen of claim 1, wherein collagen is extracted from lens capsules of an animal without the use of an enzyme.

5. A method for producing the type IV collagen of claim 1, which comprises at least steps of: (1) agitating lens capsules in a phosphate buffered saline to recover a precipitate; (2) agitating the precipitate obtained in step (1) in an aqueous acidic solution to recover a supernatant containing type IV collagen; and (3) adding salt to the supernatant obtained in step (2) to allow type IV collagen to precipitate and recovering the resulting precipitate.

6. The method of claim 5, wherein steps (1) to (3) are carried out at a low temperature.

7. The method of claim 5 or 6, wherein the phosphate buffered saline used in step (1) contains a protease inhibitor.

8. The method of claim 5, wherein the aqueous acidic solution used in step (2) contains a protease inhibitor.

9. The method of claim 5, wherein, in step (3), salt is added to the supernatant obtained in step (2) and type IV collagen is then allowed to precipitate by centrifugation.

10. The method of claim 5, which further comprises step (4) of solubilizing the precipitate obtained in step (3) with an aqueous acidic solution and then dialyzing the resultant with an aqueous acidic solution.

11. A type IV collagen derived from lens capsules which is produced by the method of claim 4 and which has a minimum molecular weight of 160 to 180 kDa measured by SDS-PAGE under reduced conditions.