Sequence comparison of pepsin-resistant segments of basement-membrane collagen α1(IV) chains from bovine lens capsule and mouse tumor

Abstract

The C-terminal peptic fragment P1 (about 518 amino acid residues) of bovine lens-capsule collagen α1(IV) chain was cleaved with CNBr and trypsin. The peptides were purified and characterized, allowing their ordering within the P1 fragment by comparison with a corresponding section of mouse collagen α1(IV) chain. About 67% of the sequence of bovine collagen fragment P1 was determined by Edman degradation. Comparison with the sequence of the corresponding mouse collagen fragment P1 showed 76% identify for positions Xaa and Yaa of the triplet structures Gly-Xaa-Yaa. Invariance was found for the positions of two non-triplet interruptions and of 3-hydroxyproline residues, pointing to the functional importance of these structures.