采用硫酸铵沉淀、Sephadex- 75 ,Sephadex- 10 0凝胶过滤层析等方法纯化海洋弧菌 (Vibriop acini) X4 B- 7菌株产生的碱性蛋白酶 ,得到电泳纯酶制品 ,并对纯化酶的性质进行了研究。结果显示 :纯酶的分子量为 2 7KD,等电点 p I=8.7,最适反应 p H9.0～ 10 .5 ,最适反应温度 5 0～ 6 0℃。ED-TA对酶活力没有影响 ,高酶浓度可以降低 SDS对酶的抑制作用 ,该酶可用于解聚组蛋白。 DNA琼脂糖凝胶电泳证明 :酶对 DNA酶有降解作用 ,而对 DNA没有降解作用 ,该酶有希望应用于核酸的提取

The alkali protease produced by Vibrio pacini (X4B 7) was purified by using ammonium sulfate precipitations, Sephadex G 75 and Sephadex G 100 column chromatography. The purified enzyme exhibits a single band on SDS polyacrolymide gel electrophoresis (SDS PAGE). Its molecular weight was determined to be about 27KD according to its mobility on SDS PAGE. The pI of purified enzyme was estimated to be about 8.7 using isoelectic focusing polyacrolymide gel electrophoresis(IEF PAGE). The enzyme is stable at pH ranging from 9.0～10.5. The optimal temperature of the action of enzyme ranges from 50～60℃. The enzyme is inactivated by PMSF, but not SDS and EDTA .Moreover histone and DNaseⅠ can be digested by the enzyme, but not DNA.