【作者】 孙昌魁； 张正红； 崔富昌； 陈明； 夏蕊蕊； 张玉臻；

【Author】 Authors State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, PR China

【机构】 山东大学微生物技术国家重点实验室；

【摘要】 在pH5.6的NaAc-HAc测活体系中(5mmol·L-1),求得β-1,4-N,6-O- 二乙酰胞壁质酶R2水解Strop mutans Ingbritt的Km值为0.2065mol·L-1, Vmax值为0.1275 mol·min-1,酶催化反应的活化能(Ea)为:Ea=4.6494kJ·mol-1。采用邹氏作图法研究了NBS对酶的抑制作用动力学,测定了NBS与游离酶和酶底物复合物结合的微观速度常数。更多还原

【Abstract】 The Km is 0.2065mol·L-1, the Vmax is 0.1275 mol·min-1 for the hydrolysis of Streptococcus mutans in NaAc-HAc buffer (5mmol·L-1, pH5.6). The activation energy of the enzyme is 4.6494kJ·mol-1. The inactivations of 6-1, 4-N, 6-O-diacetylmuramidase R2 by N-bromosuccinimide (NBS) and Woodward’s reagent K have been studied using the kinetic method of the substrate reaction during inhibition of enzyme activity previously described by Tsou. During pH 5.2 to 5.8, the characters of functional groups of β-1, 4-N, 6-O-diacetylmuramidase R2 active site have been studied using the kinetic method. The pKe value of the ionization of β-1,4-N, 6-O-diacetylmuramidase R2 active site was determined to be 5.61.更多还原