昆虫来源的几丁质酶的分离纯化及酶学性质

Purification and characterization of a chitinase from Bombyx mori

摘要:

几丁质酶在真菌和昆虫的生理和发育过程中起着关键作用，该酶本身及其酶抑制剂是获取生物农药的重要途径。本研究从蚕蛹体内提取几丁质粗酶，经硫酸铵分级沉淀和Sephadex G-150分离得到几丁质酶。用SDS-PAGE测得该酶的分子量为88 kDa。水解胶体几丁质的Km值为22.3 μmol/L。酶反应的最适温度为45℃，最适pH值为6.0，金属离子和有机试剂对几丁质酶活性都有影响，其中高浓度的Mn2+对酶有较强的激活作用，而Cu2+、SDS则有较强的抑制作用。研究结果为基于几丁质酶的生物农药筛选研究奠定了基础。

Abstract:

The importance of chitinases in the physiological and developmental processes of fungi and insects makes themselves and their inhibitors important targets for biological pesticides. A chitinase was isolated from Bombyx mori and purified to electrophoretic homogeneity by ammonium sulfate precipitation and Sephadex G-150 column chromatography. The molecular mass was estimated to be about 88 kDa by SDS-PAGE, while the Km was calculated to be 22.3 μmol/L. Moveover, the optimal reaction temperature was 45?C, and the optimum pH was 6.0. The effect of metal ions and organic reagents on chitinase activity was investigated. The activity was enhanced by high concentration of Mn2+, while was strongly inhibited by Cu2+ and SDS. These results provide a basis for screening the chitinase-based biological pesticide.