CAREER: Harnessing Large Protein Conformational Changes to Perform Remarkable Chemical Reactions

职业：利用大的蛋白质构象变化来进行显着的化学反应

• 批准号: 1945174
• 负责人: Markos Koutmos
• 金额: $ 75万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-15 至 2024-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1945174&HistoricalAwards=false
• 关键词: CAREER; Harnessing; Large; Protein; Conformational

With this award, the Chemistry of Life Processes Program in the Chemistry Division is funding Dr. Markos Koutmos from the University of Michigan Ann Arbor to investigate how biological catalysts accomplish "unusual" or "improbable" chemical reactions. Vitamin B12 dependent methionine synthase (MS) is one nature's best catalysts, playing an integral role in the formation of methionine, one of the 20 commonly occurring amino acids that form proteins. MS catalyzes, or speeds up, a reaction that would be impossible under normal conditions (e.g., temperature, pressure, concentration). The Koutmos lab uses a combination of techniques, such as three-dimensional structure determinations and electron microscopy, along with reaction rate measurements, to understand how the enzyme is able to accomplish such a challenging reaction. The ultimate goal of this research is to use the enzyme as a chemical tool: reprogramming MS to catalyze novel, desired reactions for synthetic applications. This project is integrated into a public engagement program to enhance visual communication and general scientific literacy in high school and undergraduate students in cooperation with the University of Michigan Museum of Natural History. Collaboration with Fisk University chemists involves under-represented minority students in research projects at the University of Michigan during the summer.This research project seeks to uncover fundamental principles regarding how enzyme dynamics facilitate challenging chemical reactions and, ultimately, to exploit these principles in order to reprogram biological enzymes to catalyze new reactions. Transient kinetic and structural biology approaches establish how MS module arrangements support three distinct methyl transferase reactions. The information gained from the mechanistic studies informs the design of engineered MS-based proteins and unnatural/synthetic cobalamin analogs to create a customizable biocatalytic system to direct the reactivity of MS to catalyze methylations, or even alkylations, on noncanonical substrates. MS is highly flexible and contains extensive interdomain interfaces that are assembled and disassembled as needed to support the chemical reactions. This research establishes how stochastic motions, the oxidation state, and coordination environment of the cobalamin cofactor contribute to the dynamics of conformational states accessible to the enzyme. Information from this study provides insight into how large multi-modular enzymes rearrange to accomplish their reactions. The research has the potential to open a new area of research into how methyltransferases can be redesigned to address the need of chemists to efficiently and specifically transfer methyl-groups.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.

有了这个奖项，化学部的生命过程化学计划正在资助密歇根大学安阿伯的Markos Koutmos博士研究生物催化剂如何完成“不寻常”或“不可能”的化学反应。维生素B12依赖性甲硫氨酸合酶（MS）是自然界最好的催化剂之一，在形成甲硫氨酸（形成蛋白质的20种常见氨基酸之一）中起着不可或缺的作用。MS催化或加速在正常条件下不可能的反应（例如，温度、压力、浓度）。Koutmos实验室使用多种技术的组合，如三维结构测定和电子显微镜，沿着反应速率测量，以了解酶如何能够完成这样一个具有挑战性的反应。这项研究的最终目标是使用酶作为化学工具：重新编程MS以催化合成应用所需的新型反应。该项目被纳入一个公众参与计划，以提高视觉沟通和一般科学素养的高中和本科学生与密歇根大学自然历史博物馆合作。 与菲斯克大学化学家的合作涉及密歇根大学夏季研究项目中代表性不足的少数民族学生。该研究项目旨在揭示酶动力学如何促进具有挑战性的化学反应的基本原理，并最终利用这些原理重新编程生物酶以催化新的反应。瞬时动力学和结构生物学方法建立MS模块安排如何支持三个不同的甲基转移酶反应。从机理研究中获得的信息为设计工程化的基于MS的蛋白质和非天然/合成的钴胺素类似物提供了信息，以创建可定制的生物催化系统，从而指导MS的反应性以催化非典型底物上的甲基化，甚至烷基化。MS是高度灵活的，包含广泛的域间接口，根据需要组装和拆卸，以支持化学反应。这项研究建立了如何随机运动，氧化态，钴胺素辅因子的协调环境有助于酶的构象状态的动态。这项研究的信息提供了对大型多模块酶如何重新排列以完成其反应的深入了解。 这项研究有可能开辟一个新的研究领域，即甲基转移酶如何被重新设计，以满足化学家高效和特异性转移甲基的需求。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。