细菌中酶蛋白硫辛酰化途径研究进展

Advances in protein lipoylation pathways in bacteria

摘要:

硫辛酸为含有两个硫原子的八碳脂肪酸，具有很强的抗氧化性，在保健食品、化妆品和药物等领域都具有良好的应用前景。细胞中硫辛酸是重要的辅因子，影响多种α-酮酸脱氢酶活性，参与能量代谢和物质代谢。模式生物大肠杆菌中酶蛋白硫辛酰化途径研究得较为清楚，包括依赖于LipB-LipA的硫辛酸从头合成途径和依赖于LplA的硫辛酸补救合成途径。但随着研究的深入，发现不同细菌中酶蛋白硫辛酰化途径具有较高的多样性，部分细菌中GcvH蛋白也参与硫辛酰化修饰过程，相关催化酶类也不尽相同。本文系统总结了硫辛酸依赖的多酶复合体、硫辛酰修饰的结构域和GcvH蛋白，以及不同细菌中酶蛋白硫辛酰化途径多样性的研究进展，旨在为进一步了解细菌酶蛋白硫辛酰化机制、开发针对性的抗菌药物以及利用生物法高效生产硫辛酸等方面提供理论支撑。

关键词:硫辛酸;硫辛酸从头合成途径;硫辛酸补救合成途径

Abstract:

Lipoic acid is a derivative of octanoic acid with two sulfur atoms at carbon atoms 6 and 8. The strong antioxidant activity of lipoic acid makes it have a good application prospect in the fields of health food, cosmetics and medicine. Lipoic acid as an important cofactor is required for several key enzymes complexes, like α-ketoacid dehydrogenase, and it also involves in energy generation and intermediate metabolisms. The protein lipoylation pathways have been well studied in the model organism Escherichia coli, including the lipoic acid de novo synthetic pathway dependent on LipB-LipA and the lipoic acid salvage pathway dependent on LplA. However, the lipoylation pathways in different bacteria show a highly diversity. The GcvH protein in certain bacteria also participates in protein lipoylation eventhough the related enzymes are different. In this review, we comprehensively discussed the current research progress on lipoic acid dependent multiple enzyme complexes, the lipoyl domain, GcvH proteins, as well as the protein lipoylation pathways in differen bacteria, aiming to provide theoretical support for further understanding the protein lipoylation in bacteria, developing the targeted antibacterial drugs, and efficient lipoic acid production with biological methods.

Key words:lipoic acid;lipoic acid de novo synthetic pathway;lipoic acid salvage pathway