MECHANISTIC CHARACTERIZATION OF TAURINE DIOXYGENASE

牛磺酸双加氧酶的机制表征

• 批准号: 6385099
• 负责人: MATTHEW J RYLE
• 金额: $ 2.55万
• 依托单位: MICHIGAN STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-05-01 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6385099
• 关键词: Escherichia coli; Raman spectrometry; active sites; chemical kinetics; circular magnetic dichroism; electron spin resonance spectroscopy; enzyme mechanism; oxygenases; stop flow technique; taurine

Taurine/alpha-ketoglutarate (alphaKG)-dioxygenase (TauD) is an alphaKG-dependent non-heme Fe(II) containing enzyme from Escherichia coli that plays a critical role in the utilization of taurine as a sulfur source. This enzyme is mechanistically related to a variety of alpha-keto acid-dependent dioxygenases, a large class of enzymes that are essential for the metabolism of a variety of compounds. Despite the prevalence of alphaKG- dependent dioxygenases, little information is available describing the enzyme mechanism of this important enzyme class. TauD is an excellent candidate to serve as a model enzyme for characterizing the general mechanism of alpha-keto acid-dependent dioxygenases because it is small, soluble, and easily purified from a recombinant E. coli strain that overexpresses the tauD gene. I propose to study taurine catabolism by wild-type and variant forms of TauD using a variety of spectroscopic and kinetic methods. Data from these experiments will be integrated with ongoing X-ray crystal structure characterizations, being performed by our collaborators, in order to develop a detailed enzyme mechanism for taurine degradation by TauD. Additional studies will begin to explore the role of genes encoding TauD homologues that were recently discovered in pathogenic bacteria.

牛磺酸/α-酮戊二酸 (αKG)-双加氧酶 (TauD) 是一种来自大肠杆菌的 αKG 依赖性非血红素 Fe(II) 酶，在牛磺酸作为硫源的利用中发挥着关键作用。 这种酶在机制上与多种α-酮酸依赖性双加氧酶相关，这是一大类对多种化合物的代谢至关重要的酶。 尽管αKG依赖性双加氧酶很普遍，但描述这一重要酶类的酶机制的信息却很少。 TauD 是表征 α-酮酸依赖性双加氧酶一般机制的模型酶的绝佳候选者，因为它体积小、可溶且易于从过表达 tauD 基因的重组大肠杆菌菌株中纯化。我建议使用各种光谱和动力学方法研究野生型和变异型 TauD 的牛磺酸分解代谢。 这些实验的数据将与我们的合作者正在进行的 X 射线晶体结构表征相结合，以便开发 TauD 降解牛磺酸的详细酶机制。 其他研究将开始探索最近在病原菌中发现的编码 TauD 同源物的基因的作用。