报告题目：Programming multistep biosynthesis with help of megasynthases

报告人：Dr. Martin Grininger

报告时间：2024年6月24日（周一）14：00

报告地点：C07-207

邀请人：刘进轩

报告摘要：

      The type I fatty acid (FASs) and polyketide synthases (PKSs) are up to several megadalton large multienzymes, termed megasynthases, that catalyze C-C bond forming reactions in compartmentalized space. Compartmentalization is largely achieved by the transacylation function of FASs and PKSs, i.e., the enzymatic reaction responsible for selecting substrates from the bulk cytoplasm, and further relies on the specific protein architecture as well as the shuttled distribution of substrates between the enzymatic domains. Controlling the transacylation function of FASs and PKSs as well as the specificity of their C-C bond forming reactions enables the modulation of the product output of these proteins to access platform chemicals and bioactive compounds.

      Several examples for engineering megasynthases will be presented: We employed fungal and mammalian FASs for the custom synthesis of platform chemicals, among them short-chain fatty acids, aldehydes, alcohols, methylketones and lactones. Here, FAS constructs were mutated in the transferase and ketoacyl synthase domains to increase the complexity of the synthesized compounds. Further, we inserted the mammalian FAS transferase domain (MAT) into modular PKSs to enable the in vitro chemoenzymatic synthesis of new polyketides, including fluorinated 12- and 14-membered macrolactones with the same fluoro-methyl motif as in the next-generation antibiotic solithromycin.

I型脂肪酸合酶（FAS）和聚酮合酶（PKS）是高达几兆道尔顿的大型多酶，称为巨型合酶，可在区室化空间中催化C-C键形成反应。区室化主要通过FAS和PKS的转酰基化功能实现，该酶促反应负责从细胞质中选择底物；也依赖于特定的蛋白质结构以及酶结构域之间底物的穿梭分布。控制FAS和PKS的转酰基化功能以及C-C 键形成反应的特异性可以调节这些蛋白的产物种类，为平台化学品和生物活性化合物的获取提供新路线。

本报告将介绍巨型合酶工程化的几个例子。我们利用真菌和哺乳动物FAS来定制平台化学品，包括短链脂肪酸、醛、醇、甲基酮和内酯；在FAS转移酶和酮酰合酶结构域中引入突变，可以增加所合成化合物的复杂性。此外，我们将哺乳动物FAS转移酶结构域MAT插入模块化PKS中，以实现新聚酮化合物的体外酶促合成，包括合成氟化12和14元大环内酯，该类大环内酯具有与下一代抗生素——索利霉素相同的氟甲基基序。

报告人简介：

Martin Grininger是德国法兰克福大学教授，现任法兰克福大学布赫曼分子生命科学研究所（Buchmann Institute for Molecular Life Sciences）生物分子化学研究组组长。主要研究蛋白质结构与功能，并探索蛋白质在生物化学、生物医学和生物技术中的应用。采用包括生物化学、X-射线晶体学、冷冻电镜等手段对巨型合酶进行表征，以了解它们的优点和详细工作原理，然后改造这些蛋白，使它们不再执行通常的工作，而是执行与生物技术和医疗保健相关的新设计功能。在Nature Chemistry、Nature Chemical Biology、PNAS等期刊发表重要论文60余篇。