Nakagaki T, Kazim A L, Kisiel W
Blood Systems Research Foundation Laboratory, Department of Pathology, University of New Mexico School of Medicine, Albuquerque.
Thromb Res. 1990 Jun 15;58(6):593-602. doi: 10.1016/0049-3848(90)90305-v.
A protease from the venom of the tropical moccasin (Agkistrodon bilineatus) that activates protein C was purified to homogeneity by ion-exchange and gel permeation chromatography. The purified protease is a glycoprotein, and exhibited a molecular weight of 35,000 and 38,000 in SDS-PAGE under non-reducing and reducing conditions, respectively. The purified protease readily activated human protein C and steady-state kinetic parameters indicated an apparent Km for human protein C of 1.7 microM and an apparent kcat of 0.02 sec-1. Calcium inhibited the activation of human protein C by the venom protease (Ki = 93 microM). Amino-terminal sequence analysis revealed that the tropical moccasin protein C activator was highly homologous to the protein C activator isolated from Southern copperhead venom.
从热带噬鱼蛇（双线水蝮蛇）毒液中分离出一种可激活蛋白C的蛋白酶，通过离子交换和凝胶渗透色谱法将其纯化至同质。纯化后的蛋白酶是一种糖蛋白，在非还原和还原条件下，SDS-PAGE显示其分子量分别为35,000和38,000。纯化后的蛋白酶可轻易激活人蛋白C，稳态动力学参数表明，其对人蛋白C的表观Km为1.7 microM，表观kcat为0.02 sec-1。钙可抑制毒液蛋白酶对人蛋白C的激活作用（Ki = 93 microM）。氨基末端序列分析表明，热带噬鱼蛇蛋白C激活剂与从南铜头蝮蛇毒液中分离出的蛋白C激活剂高度同源。
