紫杉醇生物合成机制研究进展

Research advances on paclitaxel biosynthesis

紫杉醇是目前已发现的最具抗癌活性的天然广谱抗癌药物之一,其生产方式主要依赖于从珍稀植物红豆杉中进行分离提取以及化学半合成,因其含量稀少,生产能力受到严重的限制。随着红豆杉基因组的全解析和合成生物学的迅速发展,通过合成生物技术,构建重组工程细胞合成紫杉醇及其关键前体成为解决当前供需不平衡和资源有限的有效方法。本文针对紫杉醇生物合成途径解析、红豆杉组学分析、底盘细胞构建、关键前体合成、紫杉醇合成途径关键酶的改造及催化机理解析等相关研究进展开展系统性的综述,尤其对近期发表的关于氧杂环丁烷环形成的相关突破性研究进行了详细介绍,并基于相关进展探讨当前紫杉醇合成生物学研究面临的关键酶催化效率低下、产物杂泛性严重、具体反应顺序未知等技术挑战及生物合成紫杉醇关键中间体的未来前景。助力加强对紫杉醇合成通路和催化过程的理解,进一步实现紫杉醇的绿色、高效生物合成。

Paclitaxel(Taxol)is a natural broad-spectrum anticancer drug,which is well-known for its potent anticancer activity.Its production mainly relies on the extraction and purification from the rare Taxus plant,followed by chemical semi-synthesis.The limited natural resource for paclitaxel imposes a significant constraint on its production capacity.In recent years,with the complete decoding of the Taxus genome and the rapid development of synthetic biology,constructing recombinant cells through synthetic biology techniques has emerged as an effective method to address this challenge.Since paclitaxel biosynthesis involves more than 20 steps of complicated enzymatic reactions and about half of them are P450 enzyme-mediated hydroxylation reactions,the complete elucidation of its biosynthetic pathway remains elusive.Meanwhile,the production of paclitaxel by engineered microbes is still at the initial stage,and there are numerous by-products,which seriously compromise the efficient synthesis of paclitaxel.Therefore,this article reviews research progress related to paclitaxel synthesis pathways,Taxus omics analyses,construction of chassis cells,synthesis of key precursors,modifications of crucial enzymes,and catalytic mechanisms underlying paclitaxel biosynthesis.Special attention is given to the recent breakthrough in elucidating the formation of oxetane ring and the discovery of Taxane 1-β-and 9-α-hydroxylases.Recent advances in the study of the catalytic mechanism of Taxadiene 5-α-hydroxylase and significant progress in engineering tobacco and yeast chassis will also be commented.Furthermore,challenges and future prospects involved in the paclitaxel synthetic biology research are discussed,such as the issues of low enzyme catalytic efficiency,significant product promiscuity,unknown specific reaction sequences,and the biosynthesis of critical paclitaxel intermediates,aiming to enhance the understandings of paclitaxel biosynthetic pathways and catalytic mechanisms for greener and more efficient production of paclitaxel.