NADP-异柠檬酸脱氢酶的结构与功能  

Structure and Function of NADP-Isocitrate Dehydrogenase

作　　者：朱国萍[1] 黄恩启[1] 赵旵军[1] 

机构地区：[1]安徽师范大学生物大分子进化重点实验室,安徽芜湖241000

出　　处：《安徽师范大学学报（自然科学版）》2007年第3期366-371,共6页Journal of Anhui Normal University(Natural Science)

基　　金：国家自然科学基金(30500300);教育部科学技术研究重点项目(206066);安徽省优秀青年科技基金(06043089);安徽省引进海外留学人才基金(2005Z032);安徽省教育厅自然科学研究重点项目(2006KJ061A)

摘　　要：异柠檬酸脱氢酶(isocitrate dehydrogenase,IDH)在三羧酸(TCA)循环中催化异柠檬酸生成α-酮戊二酸,将NAD+或NADP+还原成NADH或NADPH.根据空间结构特点,NADP-依赖性IDH可分为同源二聚体IDH和单体IDH,它们对生物体的能量代谢、生物合成以及抗氧化胁迫起重要作用.当碳源贫乏时,NADP-依赖性IDH的可逆磷酸化对TCA循环和乙醛酸旁路碳通量(carbon flux)的分配起关键性调控作用.因此目前IDH是研究蛋白质的结构与功能关系、酶的催化与调节机制、蛋白质功能进化的最好模型之一.Isocitrate dehydrogenase （IDH） in the tricarboxylic acid （TCA） cycle catalyzes the conversion of isocitrate to α-ketoglutarate and the reduction of NAD^＋ or NADP^＋ to NADH or NADPH. According to the conformational characteristics, NADP-dependent IDH can be divided into homodemefic IDH and monomeric IDH, and they play a key role in the organisms for their energy metabolism, biosynthesis and resistance to oxidation stress. During growth on the poor carbon sources, the partition of carbon flux between TCA cycle and glyoxylate bypass is vitally regulated by the reversible phosphorylation of IDH. Therefore, IDH is one of the best models for investigating the relationships between protein structure and function, the mechanisms of enzyme catalysis and regulation, and the functional evolution of proteins.

关 键 词：异柠檬酸脱氢酶(IDH) NADP-依赖性IDH 同源二聚体IDH 单体IDH 

分 类 号：Q55[生物学—生物化学] Q71