苹果酸酶的分子生物学研究进展

苹果酸酶（malic enzyme，ME）是调控苹果酸代谢的关键酶，可以催化苹果酸氧化脱羧的可逆反应，产生丙酮酸和CO2，以及伴随NAD（P）^＋的还原反应。根据辅酶特异性，苹果酸酶可分为NAD^＋或NADP^＋依赖性苹果酸酶，并广泛存在于自然界中。苹果酸酶广泛地参与不同的代谢途径，包括C4植物中的固碳作用、真菌和动物中脂质合成的NADPH源泉、以及组织快速繁殖时线粒体能量的供给等。对苹果酸酶的生化特性、空间结构特点、催化机理的研究，将为代谢工程奠定基础。

Advances in Research of Molecular Biology of Malic Enzyme

Malic enzyme （ME） , important malate metabolizing enzyme, catalyzes the reversible oxidative decarboxylation of L-malate coupled with the reduction of dinucleotide cofactor NAD （ P ） ＋ to yield pyruvate and C02. These enzymes can use NAD＋ （ NAD-ME ） or NADP＋ （ NADP-ME ） as essential eofaetors and are widely distributed in most living organisms. As the catalytic products by MEs can support diverse biological processes, MEs are involved in a great number of metabolic pathways, including carbon fixation in tropical C4 plants, lipogenic NADPH production in fungi and animals, and energy production in rapidly proliferating tissues. The research on biochemical properties, crystal structure and catalytic mechanism will be the fundamental work for the future manipulation of metabolic engineering.