Reaction Specificity in Pyridoxal Phosphate Enzymes

磷酸吡哆醛酶的反应特异性

• 批准号: 1709524
• 负责人: Michael Toney
• 金额: $ 48万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-15 至 2021-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1709524&HistoricalAwards=false
• 关键词: Reaction; Specificity; Pyridoxal; Phosphate; Enzymes

The Chemistry of Life Processes Program in the Chemistry Division funds this award. Professor Michael Toney of the University of California-Davis investigates vitamin B6 dependent enzymes. Enzymes catalyze the chemical reactions of living systems, enhancing the rates of reaction by enormous amounts. A large class of metabolically-important enzymes use vitamin B6 (pyridoxal phosphate) to catalyze reactions for nitrogen utilization. As a class, these enzymes also have excellent potential for the synthesis and commercial production of high-value chemicals (such as herbicides). The goal of this research is to understand the basis for the specific production of certain chemicals by vitamin B6 dependent enzymes. To achieve this goal, a combination of studies on altered versions of vitamin B6, and laboratory enzyme evolution is underway. This funding contributes to the professional development of undergraduate and graduate students, and allows the development of an undergraduate course focused on preparing under-represented minority undergraduate students for laboratory research. Pyridoxal phosphate (also called PLP or vitamin B6) dependent enzymes are central to nitrogen metabolism in all organisms. As a group, they catalyze more than a dozen different reaction types, with each reaction type having multiple substrate specificities. Approximately 230 different PLP enzyme activities have been identified to date. The fundamental organic chemistry used to catalyze these different reactions is generally understood, but the mechanisms by which substrate and reaction specificity are achieved are not. This research has two major components: the first employs coenzyme analogues to determine the influence of coenzyme electrophilicity on reaction specificity, and the second involves laboratory reconstruction of ancestral, non-specific enzymes and recapitulation of their evolution to present day enzymes via a minimal number of critical mutations. These studies help to define the electronic and structural determinants of reaction specificity in pyridoxal phosphate dependent enzymes. This funding also contributes to professional development of undergraduate and graduate students, and allows for the development of an undergraduate course focused on preparing under-represented minority undergraduate students for laboratory research.

化学部的生命过程化学计划资助该奖项。 加州大学戴维斯分校的 Michael Toney 教授研究维生素 B6 依赖性酶。酶催化生命系统的化学反应，大大提高反应速率。 一类对代谢很重要的酶使用维生素 B6（磷酸吡哆醛）来催化氮利用反应。作为一类，这些酶在高价值化学品（如除草剂）的合成和商业化生产方面也具有巨大的潜力。本研究的目的是了解维生素 B6 依赖性酶具体生产某些化学物质的基础。为了实现这一目标，对维生素 B6 的改变版本和实验室酶进化的研究正在进行中。这笔资金有助于本科生和研究生的专业发展，并允许开发本科课程，重点为代表性不足的少数族裔本科生进行实验室研究做好准备。磷酸吡哆醛（也称为 PLP 或维生素 B6）依赖性酶是所有生物体氮代谢的核心。作为一个整体，它们催化十多种不同的反应类型，每种反应类型都具有多种底物特异性。迄今为止，已鉴定出大约 230 种不同的 PLP 酶活性。用于催化这些不同反应的基本有机化学已被普遍了解，但实现底物和反应特异性的机制尚不清楚。这项研究有两个主要组成部分：第一个部分采用辅酶类似物来确定辅酶亲电子性对反应特异性的影响，第二个部分涉及对祖先的非特异性酶进行实验室重建，并通过最少数量的关键突变重现它们向当今酶的进化。这些研究有助于定义磷酸吡哆醛依赖性酶反应特异性的电子和结构决定因素。这笔资金还有助于本科生和研究生的专业发展，并允许开发本科课程，重点是为代表性不足的少数族裔本科生进行实验室研究做好准备。