Probing the mechanism and diversity of multi-electron redox reactions in sulfite

探讨亚硫酸盐中多电子氧化还原反应的机理和多样性

• 批准号: 8331722
• 负责人: Evan Thomas Judd
• 金额: $ 4.18万
• 依托单位: BOSTON UNIVERSITY (CHARLES RIVER CAMPUS)
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8331722
• 关键词: Active Sites; Archaeoglobus fulgidus; Area; Assimilations; Binding; Biochemical; Biochemistry; Bioinorganic Chemistry; Biological Process; Biology; Catalysis; Characteristics; Complex; Coupled; Development; Disease; Electrochemistry; Electron Spin Resonance Spectroscopy; Electron Transport; Electrons; Enzymes; Escherichia coli; Film; Goals; Individual; Laboratories; Lead; Link; Measures; Methods; Mycobacterium tuberculosis; Oxidation-Reduction; Participant; Potentiometry; Process; Proteins; Protons; Reaction; Research; Research Design; Research Project Grants; Research Training; Role; Scientist; Side; Sorting - Cell Movement; Spectrum Analysis; Structure; Sulfides; Sulfite reductase; Sulfites; Sulfur; Surface; Techniques; Time; Training; Training Programs; Tuberculosis; Work; career; cofactor; cysteinyltyrosine; disulfide bond; global health; graduate student; novel; programs; protein expression; protein purification; siroheme; therapeutic target

DESCRIPTION (provided by applicant): Multi-electron redox reactions, such as those catalyzed by sulfite reductases (SiRs), are poorly understood, yet important in many biological processes. In addition, Mycobacterium tuberculosis utilizes sulfite reductase in assimilation of sulfur and is therefore a potential target for therapy. SiRs electronically couple a siroheme with a [4Fe-4S] cluster to form a redox-active catalytic center. It has been proposed that the six- electron reduction of sulfite to sulfide occurs via sequential, two-electron steps, however little is known about the precise order and timing of electron and proton transfers that occur during catalysis, or how this complex process is carried out without the formation of side products. Assimilatory (aSiRs) and dissimilatory (dSiR) type SiRs are quite diverse in their structure and cofactor arrangement. The monomeric aSiR from Mycobacterium tuberculosis (mtSiR) contains an unusual covalently-linked Cys-Tyr adjacent to the active site. The multimeric dSiR from Archaeoglobus fulgidus (afSiR) contains a second pair of siroheme-[4Fe-4S] cofactors, unavailable for substrate binding. Investigating the catalytic mechanism of mtSiR and afSiR, in parallel with the prototypical multimeric aSiR from Escherichia coli (ecSiR), will advance our understanding of multi-electron catalysis. In addition, a better understanding of the catalytic mechanism of M. tuberculosis sulfite reductase could lead to the development of targeted therapeutics, and could therefore have a profound impact on global health. This training program will require the utilization of many techniques common to biochemistry and bioinorganic chemistry such as Electron Paramagnetic Resonance, Uv-vis spectroscopy, and protein expression and purification. Hence, it will prepare the participant for a successful career as a biochemist. In addition, the training program offers training in the highly specialized area of protein electrochemistry, offering training in techniques such as Protein Film Voltammetry and potentiometry. Upon completion of this program, the participant will be well prepared to enter the workforce as a highly skilled scientist.

描述（由申请人提供）：多电子氧化还原反应，例如由亚硫酸盐还原酶（SiR）催化的反应，人们知之甚少，但在许多生物过程中很重要。此外，结核分枝杆菌利用亚硫酸盐还原酶同化硫，因此是潜在的治疗靶点。 SiRs 将西罗血红素与 [4Fe-4S] 簇进行电子耦合，形成氧化还原活性催化中心。有人提出，亚硫酸盐到硫化物的六电子还原是通过连续的双电子步骤发生的，然而，对于催化过程中发生的电子和质子转移的精确顺序和时间，或者如何在不形成副产物的情况下进行这一复杂过程，人们知之甚少。同化型 (aSiR) 和异化型 (dSiR) SiR 在结构和辅因子排列方面非常不同。来自结核分枝杆菌 (mtSiR) 的单体 aSiR 在活性位点附近含有一个不寻常的共价连接的 Cys-Tyr。来自古生球菌 (afSiR) 的多聚体 dSiR 含有第二对西罗血红素-[4Fe-4S] 辅因子，无法与底物结合。研究 mtSiR 和 afSiR 的催化机制，以及来自大肠杆菌的典型多聚体 aSiR (ecSiR)，将增进我们对多电子催化的理解。此外，更好地了解结核分枝杆菌亚硫酸还原酶的催化机制可能会导致靶向治疗的开发，因此可能对全球健康产生深远的影响。该培训计划将需要利用生物化学和生物无机化学中常见的许多技术，例如电子顺磁共振、紫外可见光谱以及蛋白质表达和纯化。因此，它将帮助参与者为生物化学家的成功职业生涯做好准备。此外，培训计划还提供蛋白质电化学高度专业化领域的培训，提供蛋白质膜伏安法和电位测定法等技术的培训。完成该计划后，参与者将为作为高技能科学家进入劳动力市场做好充分准备。