赤子爱胜蚓脱氧核糖核酸酶酶动力学研究

目的对赤子爱胜蚓中一组新型脱氧核糖核酸酶(EWDs)进行酶动力学研究。方法运用单相酶扩散法(SRED)、紫外分光光度法和林-贝氏(Lineweaver-Burk)作图法。结果EWDs的最适温度均为37℃。EWD1的最适pH为5.2,Km为1.58mg/ml,Vmax为5.36mg·ml-1·min-1;EWD2的最适pH为4.4,Km值是3.95mg/ml,Vmax值为2.87mg·ml-1·min-1;EWD3的最适pH为4.8,Km值是1.52mg/ml,Vmax值为4.89mg·ml-1·min-1。Mn2+和Ca2+是EWDs的抑制剂,Mg2+仅抑制EWD3的活性。结论蚯蚓组织中发现的此组脱氧核糖核酸酶具有特殊的酶学性质,区别于已知的脱氧核糖核酸酶类。

Enzyme kinetics of deoxyribonuclease from earthworm eisenia foetida

Objective To investigate the enzyme kinetics of a novel group of deoxyribonucleases (EWDs) from earthworm eisenia foetida. Methods Single radial enzyme-diffusion method (SRED), UV spectrophotometer analysis and Lineweaver-Burk graphing were used for the study. Results The optimum temperature of EWDs was 37℃. The optimum pH of EWD1 was 5.2, the Km and Vmax values were calculated as 1.58 mg/L and 5.36 mg·ml-1·min-1, respectively. The optimum pH of EWD2 was 4.4, the Km and Vmax values were 3.95 mg/ml and 2.87 mg·ml-1·min-1. The optimum pH of EWD3 was 4.8, the Km and Vmax values were 1.52 mg/ml and 4.89 mg·ml-1·min-1, respectively. Mn2+ and Ca2+ proved inhibitory to all EWDs, whereas Mg2+ showed inhibition to EWD3 only. Conclusion EWDs extracted from earthworm eisenia foetida present with specific enzyme kinetics which are different from those of already recognized deoxyribonucleases.