锯缘青蟹NAGase的催化机理的判断  

Estimation of catalytic mechanism for the NAGase of green crab(Scylla serrata)

作　　者：金朱兴[1] 张继平[2] 颜雅雯[3] 王勤[3] 陈清西[3] 

机构地区：[1]厦门大学海洋与环境学院,福建厦门361005 [2]广东佛山科学技术学院,广东佛山528231 [3]厦门大学生命科学学院,福建厦门361005

出　　处：《台湾海峡》2007年第1期71-75,共5页Journal of Oceanography In Taiwan Strait

基　　金：国家自然科学基金资助项目(40576066)

摘　　要：以p-硝基苯酚-β-D-氨基葡萄糖苷(pNP-NAG)为底物,研究产物类似物:p-羧基苯酚和苯酚对青蟹N-乙酰-β-D-氨基葡萄糖苷酶(NAGase,EC 3.2.1.52)活力的影响.结果表明:p-羧基苯酚和苯酚对该酶有抑制的作用,IC50分别为20.0和100.0 mmol/dm3.p-羧基苯酚和苯酚对酶的抑制均表现为竞争性类型,其抑制常数KI分别为5.03和25.67 mmol/dm3.结合产物N-乙酰-β-D-氨基葡萄糖(NAG)抑制作用表现为反竞争性类型,判断NAGase水解pNP-NAG反应为有序双双反应(Ordered Bi Bi).The effect of analog of product on N-acetyl-β-D-glucosaminidase （NAGase） from green crab （Scylla serrata） has been investigated. The results showed that p-hydroxybenzoic and phenol could inhibit the enzyme activity, and the inhibition concentration led to 50% of enzyme activity lost （IC50） was estimated to be 20. 0 mmol/dm^3 and 100 mmol/dm^3 respectively. The inhibition mechanism of p- hydroxybenzoic and phenol were following competitive mechanism and the inhibition constants （K1 ） were 5.03 and 25.67 mmol/dm^3, respectively. Considering that the inhibition mechanism of N-acetylglucosamine was of uncompetitive mechanism, we concluded that the catalytic mechanism of β-N-acetyl-D-glucosaminidase was in Ordered Bi Bi.

关 键 词：锯缘青蟹 N-乙酰-Β-D-氨基葡萄糖苷酶 产物抑制 催化机理 

分 类 号：Q356.1[生物学—遗传学]