MECHANISTIC STUDIES ON PHOSPHORUS REDOX ENZYMES

磷氧化还原酶的机理研究

• 批准号: 6733558
• 负责人: WILFRED A. VAN DER DONK
• 金额: $ 22.17万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6733558
• 关键词: NAD(P)H oxidoreductase; X ray crystallography; active sites; enzyme mechanism; enzyme substrate; enzyme substrate analog; oxidation; phosphates; phosphites; protein purification; site directed mutagenesis

DESCRIPTION (provided by applicant): Compounds containing reduced forms of phosphorus (i.e. P(III) or P(I)) are widespread in Nature. Despite this, few studies have been reported detailing investigations of enzymes that catalyze phosphorus redox chemistry. In this program, we are interested in the mechanisms of catalysis of two such proteins, phosphite dehydrogenase (PtxD) and hypophosphite dioxygenase (HtxA). These enzymes perform entirely unprecedented reactions and will be studied to gain a better understanding of their catalytic mechanisms as well as their evolutionary origin. In addition, we have shown that phosphite dehydrogenase is a versatile cofactor regeneration enzyme, and a better understanding of catalysis may allow improvements in catalytic efficiency. The studies in this grant focus on the associative vs. dissociative character of the oxidation of phosphite to phosphate by PtxD. To this end, investigations with alternative substrates and site directed mutants will be conducted, and a major focus will be devoted to obtaining crystallographic characterization. The studies on HtxA focus on potential use of alternative substrates as well as developing a fundamental understanding of the mode of catalysis.

描述（由申请人提供）：包含磷的简化形式（即P（iii）或P（i））的化合物在本质上是广泛的。尽管如此，很少有研究详细介绍了催化磷氧化还原化学的酶的研究。在该程序中，我们对两种此类蛋白质的催化机制感兴趣，磷酸盐脱氢酶（PTXD）和低磷二加氧酶（HTXA）的催化机制感兴趣。这些酶执行完全前所未有的反应，并将研究以更好地了解其催化机制以及其进化起源。此外，我们已经表明，磷酸盐脱氢酶是一种多功能辅因子再生酶，对催化的更好理解可以提高催化效率。这项赠款中的研究重点介绍了PTXD磷酸盐氧化为磷酸盐的氧化性与分离特征。为此，将对替代底物和定向突变体进行调查，并将重点放在获得晶体学表征上。 HTXA的研究集中于潜在的替代底物使用以及对催化模式的基本理解。