人肝再生增强因子FAD辅助的巯基氧化酶活性测定及其活性位点研究  

FAD-dependent sulfhydryl oxidase activity of augmenter of liver regeneration protein and its activity motif

作　　者：潘艳[1] 鞠桂芝[2] 佟明华 李茹冰 杨联萍 李修义[2] 孔祥平 

机构地区：[1]解放军458医院全军肝病中心,广东广州510600 [2]吉林大学公共卫生学院卫生部放射生物学重点实验室,吉林长春130021

出　　处：《中国病理生理杂志》2006年第11期2247-2250,共4页Chinese Journal of Pathophysiology

基　　金：广东省自然科学基金重点资助项目(No.04103063)

摘　　要：目的:建立一种灵敏、简便、有效的判断人肝再生增强因子蛋白(ALRp)巯基氧化酶活性的方法,并分析ALRp的CXXC活性结构域在其发挥酶活性中的作用。方法:通过定点突变将ALRp的CXXC结构中的一个半胱氨酸突变为丙氨酸。巯基氧化酶实验分4组:①ALR组;②ALR-FAD组;③ALR突变体-FAD组;④无蛋白对照组。以还原型谷胱甘肽(GSH)为底物,于不同时点测定每组巯基浓度。结果:ALR-FAD组巯基浓度随时间的推移不断下降;其它3组巯基浓度在整个实验中均无明显变化。结论:建立了一种半定量分析ALRp巯基氧化酶活性的方法;并证明ALRp必须在FAD辅助下发挥酶活性,且ALRp的CXXC结构是ALRp具有该酶活性必不可少的部分。AIM ： To establish a sensitive and effective method to determine whether augmenter of liver regeneration protein （ALRp） has the activity of sulfhydryl oxidase. METHODS ： The cysteine at the position of 65 in CXXC motif contained in ALRp was changed into alanine through site - directed mutation. There were four groups in the experiment ： ①ALR group; ② ALR - FAD group; ③Mutated ALR - FAD group; ④ Control group. Using GSH as substrate, at different time points, the concentration of thiol in each group was measured. RESULTS： The concentration of thiol groups in the ALR - FAD group was decreased during the time of the experiment. But the thiol in the other groups didn＇t show any significant decrease. CONCLUSION： A sensitive and effective method to determine the sulfhydryl oxidase activity of ALRp was established. ALRp is a FAD - dependent sulfhydryi oxidase, and the conserved CXXC motif is indispensable to ALRp.

关 键 词：肝再生增强因子 突变 巯基氧化酶 

分 类 号：Q503[生物学—生物化学]