Mechanism of Substrate Transformations by the Complex Iron Sulfur Molybdoenzyme (CISM) Family

复合铁硫钼酶 (CISM) 家族的底物转化机制

• 批准号: 2003752
• 负责人: Partha Basu
• 金额: $ 42万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-15 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2003752&HistoricalAwards=false
• 关键词: Mechanism; Substrate; Transformations; Complex; Iron

With this award, the Chemistry of Life Processes Program in the Chemistry Division is funding Dr. Partha Basu of Indiana University–Purdue University Indianapolis to investigate how the Complex Iron-Sulfur Molybdoenzyme (CISM) family of respiratory enzymes catalyze the reduction of a wide variety of chemicals. Respiration is an essential metabolic process that generates energy in all living systems. Many microorganisms utilize specialized enzymes to carry out anaerobic respiration where substrates such as nitrate, perchlorate, and dimethyl sulfoxide are reduced. These metabolic processes contribute to ecological diversity. Biochemical, spectroscopic, computational, and kinetic methods are used to systematically study how the structure of the active site of these CISM enzymes allows them to display substrate selectivity. This project provides graduate students and postdoctoral fellows with specialized training in enzymology, spectroscopy, and computation. In addition, the research is integrated into an outreach program that introduces high school students to the study of enzymes and attracts first-year students who are not pursuing a science degree to science. A strong emphasis of the program is to use research to convey to students from groups underrepresented in STEM careers an appreciation for science. CISM enzymes are ubiquitous and play essential physiological roles in transforming different oxyanions. This research project uses periplasmic nitrate reductase as a model enzyme and develops several mutational variants of this enzyme where the coordination environment of molybdenum is systematically modified. The kinetic analyses of the enzyme variants help develop a quantitative picture for substrate selectivity. In addition, several residues in the catalytic pocket are identified as being involved in proton shuttling and substrate binding. Mutations of these residues provide valuable information about the mechanism of the reaction. The kinetic data are placed in the context of structural and spectroscopic properties of the enzyme. The proposed research provides new detailed insights into the substrate transformations catalyzed by members of the CISM family.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

凭借该奖项，化学系的生命过程化学项目正在资助印第安纳大学-普渡大学印第安纳波利斯分校的 Partha Basu 博士研究复杂铁硫钼酶 (CISM) 呼吸酶家族如何催化多种化学物质的还原。呼吸是所有生命系统中产生能量的重要代谢过程。许多微生物利用专门的酶进行无氧呼吸，其中硝酸盐、高氯酸盐和二甲亚砜等底物被还原。这些代谢过程有助于生态多样性。 使用生化、光谱、计算和动力学方法来系统地研究这些 CISM 酶的活性位点结构如何使它们表现出底物选择性。该项目为研究生和博士后提供酶学、光谱学和计算方面的专门培训。此外，该研究还被纳入一项外展计划，该计划向高中生介绍酶的研究，并吸引不攻读科学学位的一年级学生进入科学领域。该项目的重点是利用研究向 STEM 职业中代表性不足的群体的学生传达对科学的欣赏。 CISM 酶无处不在，在转化不同的氧阴离子方面发挥着重要的生理作用。该研究项目使用周质硝酸还原酶作为模型酶，并开发了该酶的几种突变变体，其中钼的配位环境被系统地改变。酶变体的动力学分析有助于形成底物选择性的定量图景。此外，催化袋中的几个残基被鉴定为参与质子穿梭和底物结合。这些残基的突变提供了有关反应机制的有价值的信息。动力学数据置于酶的结构和光谱特性的背景下。拟议的研究为 CISM 家族成员催化的底物转化提供了新的详细见解。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Kinetic consequences of the endogenous ligand to molybdenum in the DMSO reductase family: a case study with periplasmic nitrate reductase

• DOI: 10.1007/s00775-020-01833-9
• 发表时间: 2020-11
• 期刊: JBIC Journal of Biological Inorganic Chemistry
• 作者: Breeanna Mintmier;Jennifer M. McGarry;D. Bain;P. Basu