摘要
用计时电流法研究了烟草特有亚硝胺之一4 (N 亚硝基甲氨基) 1 (3 吡啶基) 1 丁酮(NNK)对谷氨酸脱氢酶(GLDH)催化活性的影响,测定了NNK存在与否时GLDH酶促反应的最大反应速率及米氏常数或表观米氏常数。实验结果表明,NNK对GLDH的催化活性有明显抑制作用,而且属于可逆竞争性抑制,测得在25℃,pH 8.0时抑制常数Ki为176μmol·L-1。
The effect of 4-(N-nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NNK), one of the tobacco-specific nitrosamines, on the catalytic activity of glutamate dehydrogenase (GLDH) was studied by a chronoamperometric method. The maximum reaction rate of the GLDH-catalyzed reaction and the Michaelis-Menten constant, or the apparent Michaelis-Menten constant, were determined in the Absence and presence of NNK. The results indicated that NNK could remarkably inhibit the catalytic activity of GLDH and the inhibition might be attributed to the reversible competitive inhibition. The inhibition constant was estimated to be 176 μmol·L^(-1) at 25℃ and pH 8.0.
出处
《分析科学学报》
CAS
CSCD
2005年第2期176-178,共3页
Journal of Analytical Science
关键词
谷氨酸脱氢酶
计时电流法
酶促反应
Glutamate dehydrogenase
NNK
Chronoamperometric method
