高产蛋白酶P5菌株的纯化及酶学性质

对高产蛋白酶细菌P5菌株发酵产生的蛋白酶进行初步分离纯化并研究其酶学性质。结果表明,硫酸铵饱和度为70%时,酶活性达到最高(310.44U/mL);该酶最适反应温度为40℃,在35～40℃保温5h,酶活性基本没变化;酶反应最适pH值为7.0,酶活性在pH值6.0～7.5时比较稳定。K+、Ca2+、Mg2+、Fe3+对酶活性有促进作用,Na+对酶活性基本没有影响,Hg2+和Mn2+对酶活性有抑制作用,其他金属离子对酶活性的影响随离子浓度的不同而不同。

Purification and Characterization of a Proteinase Produced by Strain P5

The protease produced by a bacterium strain P5 was purified with ammonia sulfate,and the characteristics of this enzyme was investigated.The results showed that the enzymatic activity of the protease was the highest activity(310.44 U/mL) when the concentration of ammonia sulfate is 70%.The enzyme had an optimum pH of 7.0 and temperature of 40 ℃,at the same time,it was stable in pH 6.0-7.5 and temperature of 35-40 ℃,respectively.Under the determined test condition,K+,Ca2+,Mg2+,Fe3+ could improve the enzyme activity;Na+ had no effect on enzymatic activity of the protease;whereas,Hg2+,Mn2+ inhibited the enzyme activity;other metal ions have different effects on enzyme activity according to their concentration.