A deficiency in A alpha chain's N-terminal alanine residue as a major cause of the slow coagulation of fetal fibrinogen.
To clarify the mechanism which causes the coagulation time of fetal fibrinogen to be longer than that of adult fibrinogen, the N-terminal amino acid residues of fetal fibrinogen were analyzed. The results showed that the amount of A alpha chain's N-terminal alanine residues in fetal fibrinogen was only 54% of that in adult fibrinogen. When the amount of A alpha chain's N-terminal residual alanine in adult fibrinogen was decreased to 57% of the normal level by digestion with aminopeptidase M, the adult fibrinogen yielded a prolonged thrombin time and a retarded release rate for fibrino-peptides A and B, both values approximating to those of fetal fibrinogen. The results suggest that the deficiency in alanine residue at the N-terminus of the A alpha chain is a major cause of the slow coagulation of fetal fibrinogen.
Hasegawa
N
N
Department of Physiology 1, Fujita-Gakuen Health University School of Medicine, Aichi, Japan.
Sasaki
S
S
D000409:Alanine / Q000172:deficiency*; D000596:Amino Acids / Q000032:analysis; D000626:Aminopeptidases; D001778:Blood Coagulation Disorders / Q000209:etiology*; D018826:CD13 Antigens; D004591:Electrophoresis, Polyacrylamide Gel; D005312:Fetal Blood / Q000032:analysis*; D005340:Fibrinogen / Q000032:analysis*; D005344:Fibrinopeptide A / Q000032:analysis; D005345:Fibrinopeptide B / Q000032:analysis; D005998:Glycine / Q000032:analysis; D006801:Humans; D007231:Infant, Newborn; D013918:Thrombin Time
D000596:Amino Acids; D005344:Fibrinopeptide A; D005345:Fibrinopeptide B; D005340:Fibrinogen; D000626:Aminopeptidases; D018826:CD13 Antigens; D000409:Alanine; D005998:Glycine