【摘要】 目的研究赤子爱胜蚓组织中1种脱氧核糖核酸酶(EWD3)的主要生化性质。方法采用Lowry法测定酶的蛋白含量,SDS-PAGE和MALDI-TOF方法测定相对分子质量,毛细管等点聚焦电泳法测定等电点,并测定EWD3酶的酸、碱稳定性、温度稳定性、激动剂和抑制剂对酶活性的影响及酶促反应米氏常数Km值。结果EWD3酶的蛋白含量为2.1 mg/ml,相对分子质量为63 460,等电点为6.20,Km值为1.52 mg/ml,最适pH值为4.4~5.2,不耐高温。Mg2+、Ca2+、Mn2+1、0和20 mmol/LEDTA对EWD3酶活性有抑制作用。这些参数与已发现的各种DNases相比有明显差异。结论蚯蚓组织中已发现的脱氧核糖核酸酶EWD3具有特殊的酶学特征。更多还原

【Abstract】 Objective To study the main biochemical property of a deoxyribonuclease(EWD3) from Eisenia foetida.Methods Determine the EWD3 for protein content by Lowry method,for relative molecular mass by SDS-PAGE and MALDL-TOF,for isoelectric point by capillary isoelectric focusing electrophoresis.The Km value of enzymatic reaction was also determined.Meanwhile,the acid and alkaline resistances,thermal stability,as well as effect of activator and inhibitor on enzyme activity of EWD3,were studied.Results The protein content,relative molecular mass,isoelectric point and Km value of EWD3 were 2.1 mg/ml,63460,6.20 and 1.52 mg/ml respectively.EWD3 was heat-labile,and its optimal pH value was 4.4～5.2.Magnesium,calcium and manganese ions and EDTA inhibited the enzyme activity of EWD3 significantly.All the parameters were significantly different from those of various DNases reported previously.Conclusion The deoxyribonuclease EWD3 from Eisenia foetida showed special enzymatic characters.更多还原