刺梨半乳糖内酯脱氢酶的酶促反应条件优化  

Optimization of Enzymatic Reaction Condition of L-Galactono-1,4-Lactone Dehydrogenase in Rosa roxburghii

作　　者：刘卫[1] 黄伟[1] 安华明[1] 杨曼[1] 张雪[1] 

机构地区：[1]贵州大学喀斯特山地果树资源研究所,贵州贵阳550025

出　　处：《贵州农业科学》2010年第8期213-215,共3页Guizhou Agricultural Sciences

基　　金：贵州省优秀青年科技人才培养计划项目"刺梨合成维生素C关键酶--半乳糖内酯脱氢酶的生化特性及表达特点"[黔科合人字(2007)04];国家自然科学基金项目"刺梨合成和大量积累维生素C的分子生理研究"(30660114);贵州大学研究生创新基金项目"刺梨合成AsA的生化途径及其关键酶的生化反应特性"(校研农2009008)

摘　　要：为进一步探明刺梨半乳糖内酯脱氢酶（GalLDH）的作用机理及其对维生素C（AsA）合成效率的影响,以高AsA果实刺梨为材料,研究了AsA合成关键酶——GalLDH酶促反应的动力学参数。结果表明,刺梨GalLDH反应的最适温度在30℃左右,最适pH值为8.3-9.4,以半乳糖内酯作为反应底物的Km为0.031 mM,最大反应速率Vmax=0.026 U/s。当以古洛糖内酯作为反应底物时,GalLDH也能表现约70%的活性。The dynamic parameter of GalLDH enzymatic reaction of Rosa roxburghii with high AsA content was studied to probe the mechanism of L-Galactono-1,4-Lactone Dehydrogenase and effect of L-Galactono-1,4-Lactone Dehydrogenase on AsA synthetic efficiency.The results showed that the optimum temperature and pH for GalLDH reaction was about 30℃ and 8.3～9.4,and the maximum reaction rate was 0.026U/s when the Km of L-Galactono-1,4-Lactone was 0.031mM.The activity of GalLDH could reach 70% when L-Gulonic-1,4-lactone was used as a substrate.

关 键 词：刺梨 半乳糖内酯脱氢酶 动力学特征 酶促反应 

分 类 号：S666.9[农业科学—果树学]