钙离子对凝血酶的抑制作用。

Inhibition by calcium ions of thrombin.

作者信息

Oshima G

机构信息

School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan.

出版信息

Thromb Res. 1990 May 15;58(4):383-93. doi: 10.1016/0049-3848(90)90209-u.

DOI:10.1016/0049-3848(90)90209-u

PMID:2353343

Abstract

Amidolytic activity of thrombin for Boc-Val-Pro-Arg-MCA was inhibited by CaCl2 at relatively high concentrations. Kinetic analysis showed neither competitive nor noncompetitive inhibition by CaCl2 of thrombin. The nonspecific interaction of thrombin with calcium ions prolonged fibrinogen-clotting and neutralization by antithrombin III (AT III) in the absence of heparin. However, calcium ions had no effects on rate of thrombin inactivation in dilute solution and affinity of the enzyme for Sepharose 6B. The inverse effects of calcium ions on the thrombin activities in vitro and on generation of the enzyme in plasma ex vivo depended mostly on the ion concentration.

摘要

凝血酶对Boc-Val-Pro-Arg-MCA的酰胺分解活性在相对高浓度的氯化钙作用下受到抑制。动力学分析表明氯化钙对凝血酶既无竞争性抑制也无非竞争性抑制。在没有肝素的情况下，凝血酶与钙离子的非特异性相互作用延长了纤维蛋白原的凝血时间以及抗凝血酶III（AT III）的中和作用。然而，钙离子对稀溶液中凝血酶的失活速率以及该酶与琼脂糖6B的亲和力没有影响。钙离子在体外对凝血酶活性以及在体内对血浆中该酶生成的相反作用主要取决于离子浓度。