Huang Q Q, Teng M K, Niu L W
Department of Molecular and Cell Biology, University of Science and Technology of China, Anhui, People's Republic of China.
Toxicon. 1999 Jul;37(7):999-1013. doi: 10.1016/s0041-0101(98)00228-1.
From the snake venom of Agkistrodon acutus, two proteases, acuthrombin-A and acuthrombin-C, were isolated and purified to homogeneity. They can cleave the human fibrinogen to release the fibrinopeptide A and fibrinopeptide B with specific activity of 120 and 370 NIH units/mg, respectively; the fibrinogen-clotting activity can be inhibited distinctly by PMSF or DFP or EDTA, but not by heparin. The two proteases show also arginine-esterase activity hydrolyzing some synthetic substrates such as TAME and BAEE. Additionally, they are glycoproteins with an average content of 2.4% (acuthrombin-A) and 2.1% (acuthrombin-C) neutral carbohydrates, respectively. Acuthrombin-A has a MW of 13,900 as estimated by SDS-PAGE under reduced or nonreduced conditions and 28,000 as determined by gel filtration. For acuthrombin-C, there were two protein bands corresponding to MW of 13,900 and 14,800 on SDS-PAGE with different darkness under reduced or nonreduced conditions, while its MW was estimated to be 69,000 by gel filtration. The isoelectric points were 7.5 for acuthrombin-A and 5.0 for acuthrombin-C by isoelectric focusing. Neither acuthrombin-A nor acuthrombin-C has haemorrhagic or lethal activity. Acuthrombin-A has also a small amount of activity to activate the Factor XIII.
从尖吻蝮蛇毒中分离纯化出两种蛋白酶，即尖吻蝮凝血酶 -A和尖吻蝮凝血酶 -C，且均达到了纯品状态。它们能够裂解人纤维蛋白原，释放出纤维蛋白肽A和纤维蛋白肽B，比活性分别为120和370 NIH单位/毫克；纤维蛋白原凝血活性可被苯甲基磺酰氟（PMSF）或二异丙基氟磷酸（DFP）或乙二胺四乙酸（EDTA）显著抑制，但不受肝素抑制。这两种蛋白酶还表现出精氨酸酯酶活性，能水解一些合成底物，如对甲苯磺酰-L-精氨酸甲酯（TAME）和苯甲酰-L-精氨酸乙酯（BAEE）。此外，它们都是糖蛋白，中性碳水化合物平均含量分别为2.4%（尖吻蝮凝血酶 -A）和2.1%（尖吻蝮凝血酶 -C）。在还原或非还原条件下，通过十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳（SDS-PAGE）估计，尖吻蝮凝血酶 -A的分子量为13,900，通过凝胶过滤测定为28,000。对于尖吻蝮凝血酶 -C，在还原或非还原条件下，SDS-PAGE上有两条分子量分别为13,900和14,800的蛋白带，颜色深浅不同，而通过凝胶过滤估计其分子量为69,000。通过等电聚焦测定，尖吻蝮凝血酶 -A的等电点为7.5，尖吻蝮凝血酶 -C的等电点为5.0。尖吻蝮凝血酶 -A和尖吻蝮凝血酶 -C均无出血或致死活性。尖吻蝮凝血酶 -A还有少量激活因子XIII的活性。
