镉离子对尼罗罗非鱼精巢N-乙酰-β-D-氨基葡萄糖苷酶的失活动力学（英文）  

Inhibitory kinetics of β-N-acetyl-D-glucosaminidase from Nile tilapia(Oreochromis niloticus) by cadmium

作　　者：林心宇[1] 张颖[1] 张伟妮[1] 吴方达 黄一帆[1] 黄小红[1] LIN Xinyu;ZHANG Ying;ZHANG Weini;WU Fangda;HUANG Yifang;HUANG Xiaohong(Fujian Key Laboratory of Traditional Chinese Veterinary Medicine and Animal Health, Fujian Agriculture and Forestry University, Fuzhou 350002, China;Ningde Centers for Animal Dzsease Control and Preventton Ningde 352100, China)

机构地区：[1]福建省兽医中药与动物保健重点实验室(福建农林大学),福州350002 [2]宁德市动物疾病预防控制中心,宁德352100

出　　处：《应用与环境生物学报》2018年第3期609-614,共6页Chinese Journal of Applied and Environmental Biology

基　　金：Supported by the National Natural Science Foundation of China(31572484)

摘　　要：镉离子污染对水生生物的繁殖造成了不利影响,N-乙酰-β-D-氨基葡萄糖苷酶（NAGase）被认为参与了动物的受精过程.为了解镉离子对罗非鱼繁殖的影响,以尼罗罗非鱼精巢分离获得的NAGase酶为研究对象,采用底物反应动力学方法,建立镉离子对NAGase酶的失活模型,探究镉离子对该酶活性的影响.结果显示,镉离子对NAGase表现出了可逆的抑制,对NAGase抑制的IC_（50）为40.95 mmol/L.镉离子对NAGase的抑制机理为竞争型抑制,抑制常数KI为17.13mmol/L,同时测定了微观失活速度常数.本研究表明镉离子对NAGase的抑制类型为竞争型的可逆抑制,结果可为后期研究镉离子对罗非鱼繁殖性能的研究提供理论基础.Cadmium（Cd^（2＋）） pollution in an aquatic environment can negatively affect certain reproductive parameters of aquatic animals. β-N-acetyl-D-glucosaminidase（NAGase） is considered to play an important role in the fertilization process. The aim of the present study was to investigate the effect of Cd^（2＋） on the activity of NAGase purified from the testis of Nile tilapia, toward contributing new knowledge on the breadth of negative effects of Cd^（2＋） for Nile tilapia production. The kinetic method of substrate reaction was used for this assessment, and an inhibitory model was established to study the kinetics of NAGase under inhibition by Cd^（2＋）. The results showed that Cd^（2＋） could reversibly inhibit the enzymatic activity of NAGase, and the half-maximal inhibitory concentration was estimated to be 40.95 mmol/L. Cd^（2＋） was found to be a competitive inhibitor of NAGase, and the inhibitory constant was determined to be 17.13 mmol/L. The microscopic rate constants of inactivation were also determined. Together, these findings demonstrate that Cd^（2＋） is a reversible inhibitor that can competitively inhibit NAGase. These results may provide a theoretical foundation for further studies on the reproduction of tilapia.

关 键 词：失活动力学 N-乙酰-Β-D-氨基葡萄糖苷酶 罗非鱼 镉离子 

分 类 号：Q556.2[生物学—生物化学] X174[环境科学与工程—环境科学]