The Role of Tetrel Bonding in the Reaction Mechanism of Methyltransferases

Tetrel 键在甲基转移酶反应机制中的作用

• 批准号: 2107902
• 负责人: Raymond Trievel
• 金额: $ 51.9万
• 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: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2107902&HistoricalAwards=false
• 关键词: Role; Tetrel; Bonding; Reaction; Mechanism

With the support of the Chemistry of Life Processes (CLP) Program in the Division of Chemistry, Drs. Raymond Trievel of the University of Michigan - Ann Arbor and Allison Stelling of UT-Dallas are studying an important category of enzymes known as methyltransferases. Methyltransferases are ubiquitous enzymes that play fundamental roles in the metabolism of numerous biological molecules, as well as in cell signaling and gene regulation through methylation of proteins, DNA, and RNA. In addition, methyltransferases have been implicated in numerous diseases, rendering them important targets for the design of new modulators to study their functional significance and signaling roles in biology and their dysfunction in abnormal biology or disease (relevant to cancer, cardiovascular disease, some neurological disorders, and microbial viral infections including COVID-19). Recent studies have revealed that the methyl transfer reaction catalyzed by these enzymes occurs through an unconventional type of interaction called a tetrel bond. The existence of tetrel bonds in biological macromolecules has only recently been discovered, and the contributions of these interactions to biological processes, particularly methyl transfer, remain poorly understood. The goal of this project is to characterize the functions of the tetrel bonds in methyltransferases using experimental and computational approaches. The knowledge derived from these studies will potentially inform the development of new methyltransferase linhibitors. This project will engage both undergraduate and graduate students in research in the fields of biochemistry, biophysics, structural biology and spectroscopy, affording multi-disciplinary training at the chemistry-biology interface.Methylation is a ubiquitous reaction in biology that plays a central role in the metabolism of many biological molecules, including amino acids, carbohydrates, lipids, hormones, and metabolites. In addition, methylation represents a prominent covalent modification in proteins, DNA, and RNA, which has been implicated in signal transduction and gene regulation. Most methylation reactions are catalyzed by S-adenosylmethionine (AdoMet)-dependent methyltransferases via an SN2 transfer of the AdoMet methyl group to the acceptor substrate. A recent survey of crystal structures of methyltransferases bound to AdoMet and various ligands has revealed that the AdoMet methyl group engages in tetrel bonding, a type of sigma antibonding orbital interaction similar to halogen bonding. Prior computational studies utilizing small molecule models have demonstrated that tetrel bonding between the methyl carbon atom and the nucleophilic atom represents an intermediate preceding the transition state in the SN2 reaction pathway. The discovery of tetrel bonding between the AdoMet methyl carbon atom and various ligands in methyltransferase active sites implies that this interaction is fundamental to the catalytic mechanism of these enzymes. Building on these observations, the aims of this proposal are to: 1) determine the functions of AdoMet methyl tetrel bonding in catalysis and 2) characterize the effects of methyl tetrel bonding on the AdoMet methyl vibrational modes. The functional importance of these interactions will be investigated in detail using a model methyltransferase and an interdisciplinary approach combining biochemistry, spectroscopy, crystallography, and computational chemistry. Taken together, these studies aim to elucidate the mechanism by which tetrel bonding between the AdoMet methyl group and the nucleophile facilitates methyl transfer.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，密歇根大学安阿伯分校的Raymond Trievel博士和UT达拉斯分校的Allison斯泰林博士正在研究一类重要的酶，称为甲基转移酶。甲基转移酶是普遍存在的酶，其在许多生物分子的代谢中以及通过蛋白质、DNA和RNA的甲基化在细胞信号传导和基因调控中发挥基本作用。此外，甲基转移酶与许多疾病有关，使其成为设计新调节剂的重要靶标，以研究其在生物学中的功能意义和信号传导作用及其在异常生物学或疾病中的功能障碍（与癌症、心血管疾病、一些神经系统疾病和微生物病毒感染（包括COVID-19）相关）。最近的研究表明，这些酶催化的甲基转移反应是通过一种称为四键的非常规相互作用发生的。生物大分子中四元键的存在直到最近才被发现，这些相互作用对生物过程的贡献，特别是甲基转移，仍然知之甚少。本计画的目标是利用实验与计算的方法来描述甲基转移酶中四元键的功能。从这些研究中获得的知识将可能为新的甲基转移酶抑制剂的开发提供信息。本项目将吸引本科生和研究生参与生物化学、生物物理学、结构生物学和光谱学领域的研究，提供化学-生物学界面的多学科培训。甲基化是生物学中普遍存在的反应，在许多生物分子的代谢中起着核心作用，包括氨基酸、碳水化合物、脂质、激素和代谢物。此外，甲基化代表蛋白质、DNA和RNA中的显著共价修饰，其已涉及信号转导和基因调控。大多数甲基化反应是由S-腺苷甲硫氨酸（SNMet）依赖性甲基转移酶催化的，通过SN 2将SNMet甲基转移到受体底物。最近的一项调查的晶体结构的甲基转移酶结合到cnMet和各种配体揭示，cnMet甲基从事四键，一种类型的σ反键轨道相互作用类似于卤素键。之前利用小分子模型的计算研究已经证明，甲基碳原子与亲核原子之间的四元键代表SN 2反应途径中过渡态之前的中间体。在甲基转移酶活性位点中，发现了四元甲基碳原子与各种配体之间的四元键合，这意味着这种相互作用对这些酶的催化机制是至关重要的。基于这些观察结果，本建议的目的是：1）确定在催化中的甲基四元键合的功能和2）表征甲基四元键合对甲基四元振动模式的影响。这些相互作用的功能的重要性将详细研究使用模型甲基转移酶和跨学科的方法相结合的生物化学，光谱学，晶体学和计算化学。总之，这些研究的目的是阐明的机制，通过四元键合之间的甲硫氨酸甲基和亲核试剂促进甲基transfer.This奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。