Purification and Biochemical Characterization of Trypsin inhibitor from Oyster

摘要

In this paper, the purification and biochemical characterization of the endogenous oyster (Crassostrea gigas) trypsin inhibitor were researched. A oyster trypsin inhibitor (OTI) has been purified by successive ammonium sulfate precipitation, gel filtration, affinity chromatography and high performance reversed-phase liquid chromatography. OTI has a molecular weight of approximately 5036 Da estimated by high performance size exclusive liquid chromatography. OTI was heat-, acid- and basic-stable competitive trypsin inhibitor. And OTI was double-head inhibitor with the inhibition constant (Ki) value of 1.644×10~(-2) mmol L~(-1). OTI was composed of nine kinds of amino acid, and rich in cysteine, alanine and glutamic acid. Furthermore, OTI can inhibit the proliferations of human lung adenocarcinoma A549 cell and human cervical cancer Hela cell.