重组草酸脱羧酶的表达及酶学性质研究

Expression and Characterization of Oxalate Decarboxylase

研究了重组草酸脱羧酶的表达及其酶学性质。经IPTG诱导，每克湿重菌体收获草酸脱羧酶活力820U，经Ni—NTA亲和层析酶液纯化2．07倍，酶活力回收60．38％。酶促反应的最适温度为50～55℃，最适pH值为3．5，添加EDTA及Fe^2＋对酶活力有促进作用，Mn^2＋抑制酶活。在pH4．0，温度37℃下Km值为14．53mmol／l，Vmax为133．33U／mg。

Oxalate decarboxylase was expressed and characterized in this paper. After induced by IPTG,820 U/ g （wet weight） of oxalate decarboxylase was obtained,and the enzyme was purified 2.07 fold by metal chelate affinity chromatography with a yield of 60.38%. The enzyme had an optimum temperature between 50 and 55 ℃ , and optimum pH at 3.5. Addition of EDTA or Fe2＋ would activate oxalate deearboxylase,but addition of Mn2. would inhibit the enzyme. Under condition of pH4.0,37 ℃ ,the enzyme＇ s Km was 14.53 mmol/1 with Vmax = 133.33 U/mg.