摘要
以黄粉虫幼虫为材料,采用0.05 mol/L pH 7.5 Tris-HCl缓冲液抽提、硫酸铵分级分离提取N-乙酰--βD-氨基葡萄糖苷酶(NAGase,EC 3.2.1.52),获得比活力1025 u/mg的酶制剂.研究NAGase催化pNP-NAG水解反应的动力学参数,测得米氏常数Km=0.384 mmol/L,探讨巯基乙醇对该酶活力的影响.结果表明,巯基乙醇对该酶活力具有显著的抑制作用,其抑制作用显示可逆过程,研究巯基乙醇对该酶的抑制类型,显示其抑制效应为混合型,KI和KIS分别为1.9%和9.6%.
N-acetyl-β-D-glucosaminidase （ NAGase, EC 3. 2. 1. 52 ） from Tenebrio molitor Linneeus was obtained by extraction with 0.05 mol/L pH7.5Tris-HC1 buffer and ammonium sulfate fractionation. The kinetic behavior of NAGase in catalyzing the hydrolysis of pNP-NAG was studied. The hydrolysis of pNP-NAG by NAGase follows Michaelis-Menten kinetics. The kinetic parameters for NAGase obtained from a Lineweaver-Burk plot showed that Km was equal to 0. 384 mmol/L. Effects of mercaptoethanol on NAGase were investigated. The result showed mercaptoethanol easily made enzyme inactivate. The inhibitory kinetics of mercaptoethanol on the enzyme was further studied. The result showed that it was reversible mixed typed inhibitor of the enzyme. The inhibition constants of mercaptoethanol for NAGase KI and KIS were determined to be 1.9 % and 9. 6%,respectively.
出处
《泉州师范学院学报》
2006年第4期101-105,共5页
Journal of Quanzhou Normal University
基金
福建省教育厅科技计划项目(JA04260)
