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.

吡哆醛-5 '-磷酸（PLP）是许多酶的辅因子 进行广泛的氨基酸生物转化， 胺，包括转氨、脱羧和β-和γ- 淘汰PLP能够在反应器中进行许多这些反应。 以低得多的速率不存在载脂蛋白基质， 区域特异性和立体特异性。我们研究的目标是 是确定三种PLP反应的分子细节- 依赖酶：1）来自E.大肠杆菌; 2）酪氨酸 来自柠檬酸杆菌的酚裂解酶;和3）来自假单胞菌的犬尿氨酸酶 荧光菌我们特别感兴趣的是研究 蛋白质基质提供底物和反应特异性， 这些酶。这些研究将利用X射线晶体结构 测定、快速反应动力学测量和定点 酶的诱变。