镉(Ⅱ)在酶法测定中抑制作用的研究  

Study on the Inhibition of Cadmium(Ⅱ) in Enzymatic Determination

作　　者：覃建军[1] 吴鹏[1] 柳畅先[1] 

机构地区：[1]中南民族大学化学与材料科学学院,分析化学国家民委重点实验室,武汉430074

出　　处：《分析科学学报》2008年第5期577-579,共3页Journal of Analytical Science

基　　金：中国民族大学科学基金重大项目(YZZ05018)

摘　　要：基于醇脱氢酶(ADH)催化乙醇和氧化型烟酰胺腺嘌呤二核苷酸(NAD)的反应,在最佳酶反应条件下,研究了Cd2+对酶催化的影响。发现Cd2+对ADH酶促反应有显著的抑制,抑制常数KQS为2.1 mmoL/L,属非竞争性抑制。根据在抑制剂作用下的米氏方程,可以利用酶法对镉离子进行定量测定。通过加入金属离子络合剂乙二胺四乙酸二钠(EDTA)进行了干扰消除实验,结果表明可有效消除一定浓度的Cd2+对ADH酶促反应测定底物的干扰。考察了Cd2+对ADH荧光光谱的影响,讨论了其对ADH的荧光静态猝灭作用。The influence of cadmiun（ Ⅱ ） on the enzymatic reaction under the optimum conditions based on the catalytic reaction of alcohol and the nicotinamide adenine dinucleotide oxidized form （NAD） by alcohol dehydrogenase（ADH） was studied. That enzymatic reaction was inhibited obviously by Cd^2＋. The inhibition constant（KQS） of Cd^2＋ is 2.1 mmol/L and the inhibitionis is non-competitive. According to the Michaelis-Menten equation in the presence of inhibitor, cadmiun ion can be determined by the enzymatic method. The interference of Cd^2＋ was eliminated by adding the ligand of metal ions-ethylene dinamine tetraacetic acid （EDTA）. The result indicates that interference of Cd^2＋ in certain concentration for determining substrates can be eliminated effectively. The influence of Cd^2＋ on the fluorescent spectra of ADH was investigated.

关 键 词：抑制作用 酶法测定 动力学光度法 镉(Ⅱ) 醇脱氢酶 

分 类 号：O657.3[理学—分析化学]