Complete primary structure of the collagen-binding domain of bovine fibronectin

Abstract

The complete amino acid sequence of the collagen-binding domain of bovine plasma fibronectin was determined. The fragment, generated by digestion of fibronectin with plasma and chymotrypsin, contains 340 residues (260-599 of fibronectin) with threonine and tryptophan as the amino-terminal and carboxyl-terminal amino acids, respectively. Twenty-four half-cystines and no cysteines are present in the sequence. Three glucosamine-based oligosaccharide groups are attached to Asn-399, Asn-497 and to Asn-511, respectively. Two of the 3 types (I and II) of internal homology occur in the fragment, i.e., 4 of the at least 12 stretches of type I sequence homology, fingers and 2 stretches of type II homology. The type I homology is present in 2 other plasmic fragments from fibronectin, while the type II homology was found in the collagen-binding domain only.