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

基本信息

批准号：
8722571
负责人：
Evan Thomas Judd
金额：
$ 2.84万
依托单位：
BOSTON UNIVERSITY (CHARLES RIVER CAMPUS)
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-09-01 至 2015-02-20
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8722571
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 biophysical techniques career cofactor cysteinyltyrosine disulfide bond global health graduate student novel programs protein expression protein purification siroheme therapeutic target

项目摘要

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（SIRS）催化的反应，对许多生物学过程都很重要。此外，结核分枝杆菌利用亚硫酸盐还原酶吸收硫，因此是治疗的潜在靶标。 Sirs以电子方式将Siroheme与[4FE-4S]簇搭配，形成一个氧化还原活性催化中心。已经提出，硫酸亚硫酸盐还原为硫化物是通过顺序的两电子步骤发生的，但是对于在催化过程中发生的电子和质子转移的精确顺序和时机，或者这种复杂的过程是如何在没有辅助产品形成的情况下进行的。同化（ASIR）和异化（DSIR）SIRS的结构和辅因子排列相当多样化。结核分枝杆菌（MTSIR）的单体ASIR包含与活性部位相邻的异常共价CYS-TYR。来自Archaeoglobus fulgidus（AFSIR）的多聚体DSIR包含第二对Siroheme- [4Fe-4S]辅因子，无法用于底物结合。与Escherichia Coli（ECSIR）的原型多聚体Asir同时研究MTSIR和AFSIR的催化机制，将促进我们对多电子催化的理解。此外，对结核分枝杆菌硫酸盐还原酶的催化机制有更好的了解可能导致靶向疗法的发展，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许多用于生物化学和生物无机化学的技术，例如电子顺磁共振，UV-VIS光谱以及蛋白质表达和纯化。因此，这将使参与者成为生物化学家成功的职业生涯。此外，该培训计划还提供了高度专业的蛋白质电化学领域的培训，还提供了诸如蛋白质膜伏安法和电位计量法等技术的培训。该计划完成后，参与者将做好充分的准备，成为一名高技能科学家的劳动力。