Partial amino acid sequence of human beta-thromboglobulin: structural relationship with platelet factor 4
Morgan, F.J.; Begg, G.S.; Chestermann, C.N.; Pepper, D.S.
Thrombosis Research 12(1): 171-175
1978
ISSN/ISBN: 0049-3848 PMID: 77052 Document Number: 130571
The partial amino acid sequence of human .beta.-thromboglobulin, which is shown to bear a marked structural similarity to platelet factor 4, is presented. The close structural relationship between .beta.-thromboglobulin and platelet factor 4 is clear. When a gap of 6 residues is inserted in the sequence of platelet factor 4 to maximize the homology, 31 of the initial 60 residues of .beta.-thromboglobulin are identical with those of platelet factor 4 including the 4 half-cystines. Of the remaining 29 residues shown, a further 10 are related through highly favored substitutions. .beta.-Thromboglobulin and platelet factor 4 therefore appear to have been derived from a single ancestral polypeptide, and to have retained many structural similarities.