STRUCTURE AND MECHANISM OF PLP-DEPENDENT ENZYMES

PLP依赖性酶的结构和机制

• 批准号: 2291589
• 负责人: ROBERT STEPHEN PHILLIPS
• 金额: $ 2.42万
• 依托单位: UNIVERSITY OF GEORGIA
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-09-01 至 1997-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2291589
• 关键词: Enterobacteriaceae; Escherichia coli; Pseudomonas; X ray crystallography; aminoacid metabolism; carbon carbon lyase; chemical kinetics; enzyme mechanism; enzyme structure; enzyme substrate; hydrolase; kynurenine; phenols; pyridoxal phosphate; site directed mutagenesis; tryptophanase; tyrosine

Pyridoxal-5'-phosphate (PLP) is the cofactor for a large number of enzymes performing a wide range of biological transformations of amino acids and amines, including transaminations, decarboxylations, and beta- and gamma- eliminations. PLP is capable of performing many of these reactions in the absence of an apoprotein matrix at much lower rates and without regiospecificity and stereospecificity. The goal of our proposed research is to determine the molecular details of the reactions of three PLP- dependent enzymes: l) Tryptophan indole-lyase from E. coli; 2) Tyrosine phenol-lyase from Citrobacter; and 3) Kynureninase from Pseudomonas fluorescens. We are especially interested in studying the role of the protein matrix in providing for the substrate and reaction specificity for these enzymes. These studies will utilize X-ray crystallographic structure determinations, rapid-reaction kinetics measurements, and site-directed mutagenesis of the enzymes.

吡ido虫5'-磷酸（PLP）是大量酶的辅因子 进行氨基酸和 胺，包括转运，脱羧，β-和伽马 - 消除。 PLP能够在 没有载脂蛋白基质的速率要低得多，没有 重新特定和立体特定。我们提议的研究的目标 是确定三个PLP的反应的分子细节 依赖性酶：l）来自大肠杆菌的色氨酸吲哚酶； 2）酪氨酸 柠檬酸杆菌的苯酚 - 莱斯酶； 3）假单胞菌的Kynureninase 荧光。我们特别有兴趣研究 蛋白质基质为底物和反应特异性提供 这些酶。这些研究将利用X射线晶体结构 测定，快速反应的动力学测量和定位 酶的诱变。