Anticoagulative and anticomplementary activity of endogenous inhibitor preparation from hepatopancreas of red king crab (paralithosed camtschaticus) towards human blood

Abstract

Serpins (SERinc Protease INhibitors) - is large and diverse group of proteins with similar structures, which can inhibit both serine and cysteine proteases by an irreversible suicide mechanism. A novel scrpin from hepatopancreas of Red King Crab {Paralithosed camtschaticus) was obtained and was studied its effect on the process of human blood plasma clotting. The investigated serpin shows a noticeable anticoagulative activity, which increases dramatically in the combined action with heparinc. Though the inhibitor has almost no effect on thrombin, it inhibits Cls (CI-esterase). We studied the action of the scrpin from P. camtschaticus on Cls via its competitive inhibition by CI inhibitor and the novel enzyme. The calculated inhibition constant of the scrpin from P. camtschaticus towards Cls is 2,02±0,71 M. Unlike CI inhibitor, the novel serpin from P. camtschaticus doesn't suppress fibrinolysis and at the same time prevents blood clotting. These features may be of interest for medical purposes.