Daletos Georgios, Stephanopoulos Gregory
Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, United States.
Metab Eng Commun. 2020 May 16;11:e00129. doi: 10.1016/j.mec.2020.e00129. eCollection 2020 Dec.
Isoprenoids comprise one of the most chemically diverse family of natural products with high commercial interest. The structural diversity of isoprenoids is mainly due to the modular activity of three distinct classes of enzymes, including prenyl diphosphate synthases, terpene synthases, and cytochrome P450s. The heterologous expression of these enzymes in microbial systems is suggested to be a promising sustainable way for the production of isoprenoids. Several limitations are associated with native enzymes, such as low stability, activity, and expression profiles. To address these challenges, protein engineering has been applied to improve the catalytic activity, selectivity, and substrate turnover of enzymes. In addition, the natural promiscuity and modular fashion of isoprenoid enzymes render them excellent targets for combinatorial studies and the production of new-to-nature metabolites. In this review, we discuss key individual and multienzyme level strategies for the successful implementation of enzyme engineering towards efficient microbial production of high-value isoprenoids. Challenges and future directions of protein engineering as a complementary strategy to metabolic engineering are likewise outlined.
类异戊二烯是最具化学多样性的天然产物家族之一，具有很高的商业价值。类异戊二烯的结构多样性主要归因于三类不同酶的模块化活性，包括异戊烯基二磷酸合酶、萜类合酶和细胞色素P450。这些酶在微生物系统中的异源表达被认为是生产类异戊二烯的一种有前景的可持续方法。天然酶存在一些局限性，如稳定性、活性和表达谱较低。为应对这些挑战，蛋白质工程已被应用于提高酶的催化活性、选择性和底物周转率。此外，类异戊二烯酶的天然多效性和模块化方式使其成为组合研究和生产新型天然代谢物的理想靶点。在本综述中，我们讨论了在微生物高效生产高价值类异戊二烯过程中成功实施酶工程的关键个体和多酶水平策略。同样概述了蛋白质工程作为代谢工程的补充策略所面临的挑战和未来方向。
