Biophysical Studies of Metalloenzymes

金属酶的生物物理研究

• 批准号: 2333907
• 负责人: Brian Hoffman
• 金额: $ 70.5万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-04-01 至 2028-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2333907&HistoricalAwards=false
• 关键词: Biophysical; Studies; Metalloenzymes

With the support of the Chemistry of Life Processes (CLP) program in the Division of Chemistry, Professor Brian Hoffman of Northwestern University is applying advanced paramagnetic resonance techniques to the solution of central problems in metallobiochemistry, the study of metal centers fundamental to life. These studies focus on multimetallic metalloenzymes that carry out life’s reactions and their synthetic analogues. One component focuses on the study of enzymes with Fe4 clusters and analogues with Fe3M, M = Fe or Mo. The focus is on ‘organometallic’ states of these clusters, which feature an Fe-C bond. Once thought to be rare in life, such states are now proposed as intermediates in terpenoid-biosynthesis enzymes and are found as intermediates central to the function of the world’s largest superfamily of metalloenzymes, the ‘radical-SAM (RS)’ enzymes, with over 700,000 members identified throughout all forms of life, which carry out a spectacular diversity of essential reactions. A second component will investigate the active site cofactor of isozymes of the enzyme nitrogenase, Fe7M, M = Mo, V, or Fe. In terms of societal Impact, the response to aims of teaching, training, and learning can be viewed as forming a pyramid. At the apex are intellectual/scientific contributions to the discipline and to the research community. Supporting these are contributions to the training of postdocs, graduate students, and undergraduates, not only in this group but in those of collaborators. A critical component of this outreach pyramid is an effort to broaden participation in the scientific enterprise, with focus on women and underrepresented minorities.Electron paramagnetic resonance (EPR)/electron-nuclear double resonance (ENDOR) studies of biomimetic synthetic [Fe3,M;S4]3+–alkyl/alkene/alkyne clusters, M = Fe, Mo, are expected to enhance understanding of intermediates of terpenoid-biosynthesis and RS enzymes, with comparison of the [Fe3,M;S4], M = Fe and Mo clusters offering insights into the role of the Mo in modulating the properties of the nitrogenase Fe7Mo catalytic cofactor. Furthermore, as shown by this program, the three nitrogenase isozymes function through a universal mechanism involving ten states, denoted En, n = 0-8. The n = even states of Mo-nitrogenase are EPR active and a majority have been characterized by EPR and ENDOR. In contrast, the n = odd states of the V- and Fe-nitrogenases are EPR-active, and given the mechanistic universality, their study will enable probing the catalytic n = odd states. New constructs of the nitrogenase isozymes will be used to probe whether reactivity differences among the three isozymes derive from influences of the different heterometals or from the differing isozyme active-site environments. In terms of broad scientific impact, better understanding of the nitrogenase enzyme is of great importance. It is well to remember that the enzyme nitrogenase carries out biological nitrogen fixation, the conversion of gaseous N2 to two molecules of ammonia, the biologically usable form of nitrogen and that approximately half the world’s human population depends on nitrogen fixation by nitrogenase. This project is supported by the Division of Chemistry in the Directorate for Mathematical and Physical Sciences, and by the Molecular Biophysics cluster of the Division of Molecular and Cellular Biosciences in the Directorate for Biological Sciences.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.

在化学系生命过程化学（CLP）项目的支持下，西北大学布莱恩霍夫曼教授正在应用先进的顺磁共振技术来解决金属生物化学的核心问题，金属生物化学是生命研究的基础。重点关注进行生命反应的多金属金属酶及其合成类似物，其中一个部分重点研究具有 Fe4 簇的酶和具有 Fe3M 的类似物，M = Fe。重点是这些簇的“有机金属”状态，其特征是 Fe-C 键，这种状态曾经被认为在生命中很少见，但现在建议将这种状态作为萜类生物合成酶的中间体，并发现它们是萜类生物合成酶的核心中间体。世界上最大的金属酶超家族“自由基-SAM (RS)”酶的功能，在所有生命形式中都有超过 700,000 个成员，它们发挥着惊人的作用第二个部分将研究固氮酶同工酶的活性位点辅因子 Fe7M，M = Mo、V 或 Fe 在社会影响方面，可以对教学、培训和学习的目标做出反应。被视为形成金字塔的顶端是对学科和研究界的智力/科学贡献，支持这些贡献的是对博士后、研究生和本科生的培训，不仅是在这个群体中，而且是在合作者中。 。一个这个推广金字塔的关键组成部分是努力扩大对科学事业的参与，重点关注妇女和代表性不足的少数群体。仿生合成[Fe3，M；S4的电子顺磁共振（EPR）/电子核双共振（ENDOR）研究]3+–烷基/烯烃/炔簇，M = Fe，Mo，预计将增强对萜类生物合成和 RS 酶中间体的理解，并与[Fe3,M;S4]，M = Fe 和 Mo 簇，深入了解 Mo 在调节固氮酶 Fe7Mo 催化辅因子特性中的作用。此外，如该程序所示，三种固氮酶同工酶通过通用的涉及十个状态的机制，表示为 En，n = 0-8，Mo 固氮酶的 n = 偶数状态是 EPR 活性的，并且大多数已被 EPR 和 ENDOR 表征，相反，n = 奇数状态。 V 和 Fe 固氮酶的状态具有 EPR 活性，并且鉴于其机制的普遍性，他们的研究将能够探测催化 n = 奇数状态。固氮酶同工酶的新结构将用于探测三种同工酶之间的反应性差异。源自不同异金属或不同同工酶活性位点环境的影响就广泛的科学影响而言，更好地了解固氮酶非常重要。固氮酶进行生物固氮，将气态 N2 转化为两个氨分子，这是氮的生物可用形式，并且世界上大约一半的人口依赖于固氮酶的固氮作用。数学和物理科学理事会的化学，以及生物科学理事会分子和细胞生物科学部的分子生物物理学集群。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。