Molecular Genetics of Alpha 2 Plasmin Inhibitor
α 2-Plasmin inhibitor (α 2PI), also called α 2-antiplasmin, is a plasma glycoprotein which rapidly inactivates plasmin proteolytic activity (1). Its molecular weight, deduced from the cDNA sequence and the carbohydrate content (14%), is ≅ 58 KD (2) whereas the molecular weight estimated by SDS-gel electrophoresis was 67 KD (1). The cause of the discrepancy is not known. Its concentration in human plasma was estimated to be 6.9 ± 0.6 mg/100 ml (3), which is estimated to be ≅ 1.2 μM on the assumption of MW 58KD. α 2PI is a serine proteinase inhibitor (serpin) which is able to inhibit several different “serine” proteinases, but is mainly playing a role as a primary inhibitor of plasmin-mediated fibrinolysis (4). Its congenital deficiency results in a lifelong severe hemorrhagic tendency due to premature degradation of hemostatic plugs by physiologically occurring fibrinolytic process (4–7).
KeywordsCrosslinking Site Congenital Deficiency Carbohydrate Side Chain Lysine Binding Site Coagulation Factor Xiii
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- 8.N. Aoki, M. Moroi, and K. Tachiya. Effects of α 2-plasmin inhibitor on fibrin clot lysis. Its comparison with α 2-macroglobulin. Thromb. Haemostas., 39:22 (1978).Google Scholar
- 12.Y. Sumi, Y. Nakamura, N. Aoki, M. Sakai and M. Muramatsu. Structure of the carboxylterminal half of human α 2-plasmin inhibitor deduced from that of cDNA. J. Biochem., 100 : 1339 (1986).Google Scholar
- 19.J. W. C. M. Jansen, F. Haverkate, J. Koopman, H. K. Nieuwenhuis, C. Kluft, and Th. A. C. Boschman. Influence of factor XIIIa activity on human whole blood clot lysis in vitro. Thromb. Haemostas.,57:171 (1987).Google Scholar