脲对麦芽酸性磷酸酶活力与构象的影响  

Effects of urea on activity and conformation of acid phosphatase from wheat germ.

作　　者：王黎明[1] 徐冬梅[1] 刘广深[1] 王深法[2] 

机构地区：[1]浙江大学环境科学研究所,浙江杭州310029 [2]浙江大学水土资源与环境研究所,浙江杭州310029

出　　处：《浙江大学学报（农业与生命科学版）》2004年第3期296-299,共4页Journal of Zhejiang University:Agriculture and Life Sciences

基　　金：国家自然科学基金项目资助(49973031).

摘　　要：应用荧光光谱、紫外差光谱等检测手段研究麦芽酸性磷酸酶经脲变性后的分子构象与活力的变化情况,结果表明,低浓度的脲(<2mol/L)微扰了酶的活性部位而使其局部构象发生变化,使酶的荧光强度略有下降,荧光发射峰位红移,酶活力下降.继续增大脲浓度,酶的整体构象被破坏,酶荧光强度增加,发射峰位红移,酶活力仍然呈下降趋势.荧光强度的增加和最大发射峰位的红移是酶变性失活的一个指标,酶活力的变化快于酶分子整体构象的变化,说明麦芽酸性磷酸酶的活性部位位于柔性较大的区域.Changes in conformation and activity of acid phosphatase from wheat germ following denaturation of the enzyme by urea solutions of different concentrations were measured by the shift in fluorescence and differential UV-absorption spectrum. Urea concentrations lower than 2.0 mol/L led to decrease in fluorescence intensity accompanied by a red shift of emission peak as well as reduction in ACPase activity due to its action on the active site and partial change of the enzyme conformation. The degree of red shift in fluorescence emission peak of ACPase tended to increase with increasing concentrations of urea while the trend of decrease in ACPase activity was maintained. The increase in fluorescence intensity and the red shift in emission peak were the indicators of enzyme inactivation. There was evidence that inactivation of the enzyme occurred more rapidly than its conformational change in urea solutions. It is suggested that the active site of the enzyme is situated in a limited area of the enzyme molecule which is more flexible.

关 键 词：酸性磷酸酶 脲 活性 溶液构象 

分 类 号：X132[环境科学与工程—环境科学] S154.2[农业科学—土壤学]