蕲蛇蛇毒中凝血酶样酶的分离纯化与特性

Purification and characterization of a thrombin-like enzyme from Agkistrodon acutus

蕲蛇粗毒经DEAE -SephadexA - 5 0、POROS 5 0HS及TSKG30 0 0SW分离纯化 ,得到 1个具有凝血酶活力的峰 .该峰经SDS -PAGE和PAGE检测均为一条带 ,分子量约 2 8.0kDa ,加DTT处理后 ,拆分为约 14.8kDa的亚基 .其凝血酶活力为 14.7NIHu/mg ,精氨酸酯酶活力为 2 1.98TAMEμmol/mg·min .该组分具有激活因子ⅩⅢ的活性 ,但没有明显的出血反应 .肝素不影响该组分的凝血酶和精氨酸酯酶活性 ,EDTA、PMSF、DFP则会产生不可逆抑制作用 ,表明该组分属于金属蛋白 .

The production of thrombin-like enzymes is studied in Agkistrodon acutus, using anion-exchange chromatography (DEAE-Sephadex A-50),followed by cation-exchange chromatography (POROS 50 HS) and TSK G3000SW gel filtration chromatography. One fraction with fibrinogen-clotting activity is purified to homogeneity determined by SDS-polyacrylamide gel electrophoresis and polyacrylamide gel electrophoresis, which is of apparent molecular weight of about 28,000 under nonreduced conditions and 14,800 under reduced conditions as determined respectively by SDS-PAGE. It shows fibrinogen-clotting activity of 14.7 NIH u/mg on bovine fibrinogen and arginine-easterase activity of 21.98 μ?mol/mg·min on TAME). Both activities are inhibited irreversibly by EDTA、 PMSF、 DFP, but not by heparin, which indicates that the fraction belongs to metalloprotein. The fraction has a small amount of activity to activate coagulation factor ⅩⅢ and has no haemorrhagic activity.