摘要
研究了芳腈水合酶催化水合3-氰基吡啶生成尼克酰胺的反应条件及影响因子.酶反应的最适pH为8.0,最适温度为25℃.酶在pH8.5于25℃保温4小时或在25—30℃于pH8.0保温3小时是稳定的.反应液中加入Fe^(3+)(1.5 mmol/L)可使酶活力增加 50%,而加入NH_4^+(300 mmol/L)则使酶活降低了67%.Ag^+和 Hg(2+)”强烈地抑制酶反应活性,在浓度均为 5mmol/L时,抑制率分别为99.7%和100%.NaCN(50 mmol/L)和苯甲腈(100 mmol/L)对酶活性的抑制率分别为78%和85%.该酶作用于 3-氰基吡啶的Km为62.5 mmol/L,V_(max)为85.8 μmol·min^(-1)·mg^(-1).
The optimum reaction conditions of aromatic nitrile hydratase catalyzing hydration of 3-cyanopyridine to nicotinamide and effectors on the reaction have been
studied. The optimum pH of the enzymatic reaction was 8. 0,the optimum temperature
9 was 25 C. The enzyme was stable at 25-30℃ and pH 8.0 for 3 hours or at 25℃and pH
8. 5 for 4 hours. Addition of Fe3+ (1. 5 mmol/L) enhanced activity for 50%, whereas addition of NH4+(300 mmol/L)decreased activity for 67%. Metal ions such as Ag+ and Hg2+ (both 5 mmol/L)inhibited strongly enzyme activity, inhibition were 99. 7% and 100% .respectively. NaCN(50 mmol/L) and benzonitrile (100 mmol/L)inhibited activity for 78% and 85% ,respectively. The Km of the enzyme for 3-cyanopyridine was 62. 5 mmol/L,Vmax was 85. 8 μmol. min-1. mg-1.
出处
《微生物学报》
CAS
CSCD
北大核心
1994年第5期367-371,共5页
Acta Microbiologica Sinica
基金
国家自然科学基金资助项目
关键词
3-氰基吡啶
水合酶
马红球菌
3-cyanopyridine,Aromatic nitrile hydratase,Nicotinamide
