Joint Laboratory for Translational Cancer Research of Chinese Medicine of the Ministry of Education of the People's Republic of China, International Institute for Translational Chinese Medicine, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, P. R. China.
Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P. R. China.
J Agric Food Chem. 2022 Jul 6;70(26):8075-8084. doi: 10.1021/acs.jafc.2c03011. Epub 2022 Jun 21.
is an important economic plant that is rich in lipophilic triterpenols with pharmacological activities including antiallergic, anti-inflammatory, and anticancer activities. However, the key enzymes related to triterpene biosynthesis have seldom been studied in . Oxidosqualene cyclases (OSCs) are the rate-limiting enzymes related to triterpene biosynthesis. In this study, seven putative genes () were mined from the transcriptome. Six CsOSCs were characterized for the biosynthesis of diverse triterpene skeletons, including α-amyrin, β-amyrin, δ-amyrin, dammarenediol-II, ψ-taraxasterol, taraxasterol, and cycloartenol by the heterologous expression system. CsOSC3 was a multiple functional α-amyrin synthase. Three key residues, Trp260, Tyr262, and Phe415, are critical to the catalytic performance of CsOSC3 judging from the results of molecular docking and site-directed mutagenesis. These findings provide important insights into the biosynthesis pathway of triterpenes in .
是一种重要的经济植物，富含具有抗过敏、抗炎和抗癌活性的亲脂性三萜醇。然而，在 中，与三萜生物合成相关的关键酶很少被研究。角鲨烯环化酶（OSCs）是与三萜生物合成相关的限速酶。在这项研究中，从 转录组中挖掘了 7 个假定的 基因（）。通过异源表达系统，对 6 个 CsOSC 进行了表征，用于合成多种三萜骨架，包括 α-香树精、β-香树精、δ-香树精、达玛烯二醇-II、ψ-蒲公英甾醇、蒲公英甾醇和环阿屯醇。CsOSC3 是一种多功能的 α-香树精合酶。从分子对接和定点突变的结果来看，三个关键残基 Trp260、Tyr262 和 Phe415 对 CsOSC3 的催化性能至关重要。这些发现为 中三萜类化合物的生物合成途径提供了重要的见解。
