MECHANISTIC CHARACTERIZATION OF TAURINE DIOXYGENASE

牛磺酸双加氧酶的机制表征

• 批准号: 6134771
• 负责人: MATTHEW J RYLE
• 金额: $ 3.24万
• 依托单位: MICHIGAN STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-05-01 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6134771
• 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（Alphakg） - 二氧酶（TAUD）是一种依赖于大肠杆菌的酶的α-依赖性的非血红素Fe（II），在牛磺酸作为硫源的利用中起着至关重要的作用。 该酶在机械上与多种α-酮酸依赖性双氧酶有关，这是一大类对于多种化合物的代谢必不可少的酶。 尽管α-依赖性二氧酶的普遍存在，但很少有信息可用，描述了这种重要酶类的酶机制。 TAUD是作为模型酶的绝佳候选者，用于表征α-酮酸依赖性的二氧酶的一般机制，因为它是小的，可溶的且易于从重组大肠杆菌菌株中纯化的，从而过表达了Taud基因。我建议使用多种光谱和动力学方法研究野生型和变异形式的牛磺酸分解代谢。 这些实验的数据将与我们的合作者进行的持续的X射线晶体结构表征集成在一起，以开发taud的详细酶机制来使牛磺酸降解。 其他研究将开始探索编码最近在致病细菌中发现的TAUD同源物的基因的作用。