苹果酸脱氢酶的结构及功能

Structure and function of malate dehydrogenases

苹果酸脱氢酶(MDH)可以催化苹果酸与草酰乙酸间的可逆转换,主要参与TCA循环、光合作用、C4循环等代谢途径。苹果酸脱氢酶可分为NAD-依赖性的MDH(NAD-MDH)和NADP-依赖性的MDH(NADP-MDH)。在所有真核生物和大部分细菌中,MDH通常形成同源二聚体,在少数细菌中为四聚体。不同来源的MDH催化机制和它们的动力学性质十分类似,显示了它们具有高度的结构相似性。MDH的功能多样,包括线粒体中的能量提供和植物的活性氧代谢等。回顾了苹果酸脱氢酶在生理学、医学、农学领域的研究进展,并针对其生化特性、空间结构特点、催化机理等生物学功能的分子生物学进展进行了综述。

Malate dehydrogenases （MDHs） may catalyze the reversible conversion between malate and oxaloacetate, which play a key role in many metabolic pathways such as TCA cycle, photosynthesis, CA cycle and so on. MDHs are divided into NAD-dependent MDHs and NADP-dependent MDHs, which usually are homodimeric molecules in most organisms, including all eukaryotes and the most bacterial species （some bacterial MDHs are tetramer）. The enzymes share a common catalytic mechanism and their kinetic properties are similar, which demonstrate a high degree of structural similarity. The functions of MDHs are biological diversity, including energy generation in mitochondrial, reactive oxygen species metabolism in plants, etc. Based on the biochemistry, stereo conformation and catalysis mechanism, the advances of MDHs in molecular biology, physiology, medicine and agriculture are discussed.