细胞色素P450在植物三萜和甾醇骨架修饰中的功能研究进展

Advances in the function of cytochrome P450 in structural modifications of triterpenoid and sterol skeletons in plants

植物三萜类化合物在植物生长发育、抵御逆境胁迫与病虫害、生物间相互作用以及传递信息等方面发挥重要作用,植物甾醇具有重要的药用价值.细胞色素P450单加氧酶(CYP450)是参与植物代谢的最大酶家族,在三萜及甾醇骨架结构多样化及功能化修饰中具有关键作用.到目前为止,研究发现约有80个CYP450参与植物三萜代谢,包括亚家族CYP51H, CYP71A, D, CYP72A, CYP81Q, CYP87D, CYP88D, L, CYP93E, CYP705A, CYP708A和CYP716A, C, E, S, U, Y,它们参与包括特定病原体的化学防御功能和药理活性的三萜及其皂苷类化合物的代谢.亚家族CYP51G, CYP85A, CYP90B-D, CYP710A, CYP724B和CYP734A与甾醇和类固醇激素的生物合成有关.本文针对CYP450基因在三萜及甾醇化合物形成过程中不同位点的修饰功能进行概述,重点探讨了陆地植物CYP450基因11个家族的进化及在双子叶、单子叶植物中五环三萜物质合成过程中的功能.以期为充分利用具有重要价值的抗肿瘤、抗艾滋病的三萜物质的合成生物学的研究及其代谢调控提供进一步的理论依据.

Plant triterpenes play important roles in plant growth and development, stress tolerance, pest and disease resistance, biological interactions, and signal transduction. Plant sterols possess important medicinal properties. Cytochrome P450 monooxygenase （CYP450） is the largest family of enzymes involved in plant metabolism, and the members of this family play keys role in the diversification and functional modifications of triterpenoid and sterol skeletons. To date, research has identifed nearly 80 CYP450 enzymes involved in triterpene metabolism in plants, including the subfamilies CYP51H, CYP71A, D, CYP72A, CYP81Q, CYP87D, CYP88D, L, CYP93E, CYP705A, CYP708A, and CYP716A, C, E, S, U, Y. Together, they participate in the metabolism of triterpenoids and their saponins as well as chemical defense functions and pharmacological activities against specific pathogens. Enzymes in the subfamilies CYP51G, CYP85A, CYP90B-D, CYP710A, CYP724B, and CYP734A are generally involved in biosyntheses of sterols and steroidal hormones. In this article, we summarized modification functions of different CYP450 gene loci in biosyntheses of triterpenes and sterols, focusing on the evolution of 11 CYP450 gene subfamilies in terrestrial plants and their roles in biosyntheses of pentacyclic triterpenoids of dicotyledonous and monocotyledonous plants. We aim to provide a theoretical basis for the comprehensive use of anti-tumor and anti- acquired immunodeficiency syndrome triterpenoids in synthetic biology and metabolic regulation.