Amino acid sequence studies on the α chain of human fibrinogen. Characterization of 11 cyanogen bromide fragments

Abstract
The .alpha. chain of human fibrinogen consists of 600 .+-. 25 amino acid residues, 10-11 of which are methionines. Identified and characterized were 11 cyanogen bromide peptide fragments of 2, 3, 26, 28, 28, 37, 51, 56, 60 .+-. 5, 64 .+-. 5, and 260 .+-. 20 residues, respectively. The sequences of 5 of these and a portion of a 6th were reported previously. Complete amino acid sequences of another of these fragments (56 residues), partial sequences for 4 others and a preliminary characterization of the largest fragment were elucidated. The sequences of some of these newly reported fragments reveal an internal homology in the .alpha. chain, as well as structural similarities to the corresponding portions of the .beta. and .gamma. chains.