DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, 1206 W Gregory Dr, Urbana, IL 61801, USA.
Department of Chemistry, The University of Texas at Austin, 105 E 24th St, Austin, TX 78712, USA.
Angew Chem Int Ed Engl. 2023 Jan 26;62(5):e202212440. doi: 10.1002/anie.202212440. Epub 2022 Dec 20.
Engineering enzymes with novel reactivity and applying them in metabolic pathways to produce valuable products are quite challenging due to the intrinsic complexity of metabolic networks and the need for high in vivo catalytic efficiency. Triacetic acid lactone (TAL), naturally generated by 2-pyrone synthase (2PS), is a platform molecule that can be produced via microbial fermentation and further converted into value-added products. However, these conversions require extra synthetic steps under harsh conditions. We herein report a biocatalytic system for direct generation of TAL derivatives under mild conditions with controlled chemoselectivity by rationally engineering the 2PS active site and then rewiring the biocatalytic pathway in the metabolic network of E. coli to produce high-value products, such as kavalactone precursors, with yields up to 17 mg/L culture. Computer modeling indicates sterics and hydrogen-bond interactions play key roles in tuning the selectivity, efficiency and yield.
由于代谢网络的固有复杂性和对体内高催化效率的需求，用具有新颖反应性的工程酶来应用于代谢途径以生产有价值的产品是极具挑战性的。三乙酰基-δ-内酯（TAL）是由 2-吡喃酮合酶（2PS）自然生成的平台分子，可以通过微生物发酵生产，进一步转化为有价值的产品。然而，这些转化需要在苛刻的条件下进行额外的合成步骤。我们在此报告了一种生物催化系统，通过合理设计 2PS 活性位点，在温和条件下直接生成 TAL 衍生物，并通过重新布线大肠杆菌代谢网络中的生物催化途径，以可控的化学选择性生成高附加值产品，如卡瓦内酯前体，产率高达 17 mg/L 培养物。计算机建模表明，立体和氢键相互作用在调节选择性、效率和产率方面起着关键作用。
