中文摘要：

通过离子交换和凝胶过滤层析从湖南产尖吻蝮蛇毒中分离纯化出1个抗补体活性蛋白AACI—I．还原与非还原SDS—PAGE测得其表观分子质量分别为26kD和22kD，等电聚焦电泳显示其等电点为pH8．9．它能抑制补体经典途径和替代途径的溶血，且该作用具有量效和时效性．AACI—I可依次水解纤维蛋白原的A仅、SiS、^y链，此活性能被EDTA、EGTA和1，10-phenanthroline完全抑制，不受PMSF、SBTI作用影响．同时，该蛋白无精氨酸酯酶活性，提示AACI—I是金属蛋白酶．另外，AACI—I具有azocasein水解活性和水肿活性，当0．01μg／g AACI—I注射小鼠足趾，其诱导肿胀率约为（14．06±6．78）％，而小鼠皮下注射2．6μg／gAACI．I后没有发现其有出血毒活性．

英文摘要：

An anticomplementary protein AACI-I was purified from Agkistrodon acutus venom by a combination of ion-exchange and gel filtration chromatography.Its apparent molecular weight was estimated as 26 kD and 22 kD by SDS-PAGE under reducing and non-reducing conditions,respectively.Its isoelectric point was pH 8.9 by IEF.It inhibits serum complement haemolytic activity both via classical and alternative pathway in a dose,time-dependent fashion.AACI-I could cleave Aα,Bβ,γ chain of fibrinogen successively.This activity was inhibited by EDTA,EGTA,1,10-phenanthroline,but not PMSF or soybean trypsin inhibitor,while it has no arginine esterase activity,indicating that AACI-I was a metalloproteinase.Furthermore,AACI-I exhibited proteolytic activity toward azocasein and it has edema activity,as AACI-I was injected in the foot pad of mice with dose of 0.01 μg /g body weight.The ratio of swelling was calculated as（14.06 ± 6.78）%,and there was no hemorrhagic point after injected subcutaneously into mice with dose of 2.6 μg /g body weight.