Department of Chemistry, University of New Brunswick, Fredericton, NB, Canada.
Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, China.
Nat Commun. 2024 Jan 11;15(1):457. doi: 10.1038/s41467-024-44797-z.
The antiarrhythmic drug ajmaline is a monoterpenoid indole alkaloid (MIA) isolated from the Ayurvedic plant Rauvolfia serpentina (Indian Snakeroot). Research into the biosynthesis of ajmaline and another renowned MIA chemotherapeutic drug vinblastine has yielded pivotal advancements in the fields of plant specialized metabolism and engineering over recent decades. While the majority of vinblastine biosynthesis has been recently elucidated, the quest for comprehending ajmaline biosynthesis remains incomplete, marked by the absence of two critical enzymes. Here, we show the discovery and characterization of these two elusive reductases, alongside the identification of two physiologically relevant esterases that complete the biosynthesis of ajmaline. We show that ajmaline biosynthesis proceeds with vomilenine 1,2(R)-reduction followed by its 19,20(S)-reduction. This process is further modulated by two root-expressing esterases that deacetylate 17-O-acetylnorajmaline. Expanding upon the successful completion of the ajmaline biosynthetic pathway, we engineer the de novo biosynthesis of ajmaline in Baker's yeast.
抗心律失常药物阿马林是从印度蛇根木（印度蛇根草）中分离出的单萜吲哚生物碱（MIA）。对阿马林和另一种著名的 MIA 化疗药物长春碱生物合成的研究，在过去几十年中为植物特化代谢和工程领域带来了重大进展。虽然最近已经阐明了长春碱生物合成的大部分内容，但对阿马林生物合成的研究仍不完整，其特征是缺少两种关键酶。在这里，我们展示了这两种难以捉摸的还原酶的发现和特性，以及两种生理相关酯酶的鉴定，它们完成了阿马林的生物合成。我们表明，阿马林生物合成是通过vomilenine 1,2（R）-还原，然后是 19,20（S）-还原进行的。这一过程进一步受到两种在根部表达的酯酶的调节，这些酯酶使 17-O-乙酰基去乙酰化norajmaline。在成功完成阿马林生物合成途径的基础上，我们在面包酵母中设计了阿马林的从头生物合成。
