Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, No. 5 South Zhongguancun Street, Beijing, 100081, China.
Beijing Institute of Technology (Tangshan), Translational Research Center, Hebei, China.
Appl Microbiol Biotechnol. 2024 Feb 7;108(1):195. doi: 10.1007/s00253-024-13030-8.
Pentacyclic triterpenoids exhibit a wide range of biological activities which have wide applications in the food, cosmetics, and pharmaceutical industries. High-performance chassis strains have been developed for the production of various pentacyclic triterpenoids, e.g., lupane-type and oleanane-type triterpenoids. The production of common pentacyclic triterpenes and their derivatives is limited by the poor activity of typical pentacyclic triterpene synthases (PTSs). However, a general strategy applicable to typical PTSs is still lacking. As typical pentacyclic triterpenes are derived from the baccharenyl cation, engineering the non-active-site residues in the MXXXXR motif might be beneficial for the catalytic efficiencies of typical PTSs by the stabilization of the baccharenyl cation. Here, we develop a general strategy for improving the activity of typical PTSs. As a proof of concept, the activity of three PTSs such as lupeol synthase, β-amyrin synthase, and α-amyrin synthases was significantly increased up to 7.3-fold by site-directed saturation mutagenesis. This strategy could be applied to improve the activity of various typical PTSs. KEY POINTS: • The strategy could be applied to typical PTSs for improving the activity. • The catalytic activity of typical PTSs was significantly increased.
五环三萜类化合物具有广泛的生物活性，在食品、化妆品和制药行业有广泛的应用。已经开发出了高性能底盘菌株，用于生产各种五环三萜类化合物，如羽扇豆烷型和齐墩果烷型三萜类化合物。由于典型的五环三萜合酶（PTSs）活性较差，常见五环三萜及其衍生物的生产受到限制。然而，仍然缺乏适用于典型 PTSs 的一般策略。由于典型的五环三萜类化合物是从 baccharenyl 阳离子衍生而来的，因此通过稳定 baccharenyl 阳离子，对 MXXXXR 基序中的非活性位点残基进行工程改造可能有利于典型 PTSs 的催化效率。在这里，我们开发了一种提高典型 PTSs 活性的通用策略。作为概念验证，通过定点饱和突变，使三萜类化合物如羽扇豆醇合酶、β-香树脂醇合酶和α-香树脂醇合酶的活性显著提高了 7.3 倍。该策略可应用于提高各种典型 PTSs 的活性。关键点：• 该策略可应用于典型 PTSs 以提高其活性。• 典型 PTSs 的催化活性显著提高。
