Understanding the specificity and non-native catalytic activity of PLP-dependent enzymes

项目摘要 依赖于PLP的酶是用途最广泛的生物催化剂之一，可以催化多种不同的 化学变化。它们在自然界中分布广泛，在新陈代谢和许多 细胞过程。因此，研究PLP酶对于我们理解生物学和发展具有重要意义。 治疗学。由于它们精致和多功能的催化活性，依赖于PLP的酶也是 杰出的生物催化剂，能够构建各种结构复杂和具有生物活性的天然产品；以及 非正则氨基酸和手性胺不对称合成不可缺少的生物催化工具 制药公司。然而，尽管迄今为止有大量依赖PLP的酶的特征，我们的 预测、操纵和驾驭他们的活动的能力在很大程度上仍然有限。这项研究计划希望 通过集成发现、机械研究和生物催化应用来填补知识空白 系统、全面地研究了四种碳-碳(C-C)键的形成和裂解PLP 酶，包括我们最近发现的依赖PLP的曼尼希环酶。这些酶代表了 PLP酶因其特殊的活性，与现有的合成效用互补而成为前沿 生物催化剂，以及与特征良好的PLP酶家族的意外进化关系。所有建议 AIMS得到了我们实验室收集的强有力的初步数据的支持。我们的首要目标是了解 化学和底物的特异性并利用这一理解来揭示以前未知的功能 研究PLP依赖的酶，并探索它们的非天然催化作用。最终，拟议的研究将 扩大了我们对PLP酶学的机理理解，为新陈代谢提供了新的思路 氨基酸生物合成的生物催化工具。

Project Summary PLP-dependent enzymes are one of the most versatile biocatalysts and catalyze a diverse range of chemical transformations. They are widespread in nature and play critical roles in metabolism and numerous cellular processes. Studying PLP enzymes is hence important for us to understand biology and develop therapeutics. Because of their exquisite and versatile catalytic activity, PLP-dependent enzymes are also remarkable biocatalysts to build diverse structurally complex and bioactive natural products; and are indispensable biocatalytic tools for asymmetric synthesis of noncanonical amino acids and chiral amine pharmaceuticals. However, despite the vast number of PLP-dependent enzymes characterized to date, our abilities to predict, manipulate, and harness their activities are still largely limited. This research program desires to fill the knowledge gap by integrating discovery, mechanistic investigation, and biocatalytic application to systematically and comprehensively study four types of carbon-carbon (C-C) bond forming and cleaving PLP enzymes, including our recently discovered PLP-dependent Mannich cyclase. These enzymes represent the frontier of PLP enzymology because of their unusual activity, complementary synthetic utility to existing biocatalysts, and unexpected evolutionary relationship with well-characterized PLP enzyme family. All proposed aims are supported by strong preliminary data gathered in our laboratory. Our overarching goal is to understand the chemical and substrate specificity and leverage this understanding to uncover previously unknown functions of PLP-dependent enzymes and explore their non-native catalytic utility. Ultimately, the proposed research will expand our mechanistic understanding on PLP enzymology, shed new light on metabolism, and provide novel biocatalytic tools for amino acid biosynthesis.