Probing Dynamics Within an Enzyme Family

探索酶家族内的动力学

• 批准号: 0820567
• 负责人: Elan Eisenmesser
• 金额: $ 36.98万
• 依托单位: University of Colorado at Denver
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2011-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0820567&HistoricalAwards=false
• 关键词: Probing; Dynamics; Within; Enzyme; Family

Intellectual Merit: Enzymes are proteins that must undergo complex movements in order to catalyze their biological reactions. A relatively recent discovery is that enzymes must be inherently flexible and that enzymes undergo motions that are localized to their active sites even in the absence of substrates. These inherent movements have, in a sense, been pre-programmed for their catalytic function, but exactly what this relationship is and how they relate across a family of enzymes remains unknown. Although the genomics era has provided both sequence and structural information, little has been learned with regard to enzyme dynamics. Such knowledge will be instrumental in understanding the evolutionary pressures that dictate protein dynamics in addition to those that dictate both sequence and structure. Thus, the focus of this research is to understand how enzymes, and proteins in general, have evolved to undergo their dynamic movements by investigating the relationship between sequence, structure, dynamics, and function among a family of enzymes. The current project involves the first investigation comparing dynamic behavior on the same timescales as biological processes (micro-millisecond timescales) within a family of human enzymes. The dynamics behavior of multiple human cyclophilin family members will be compared using recently developed nuclear magnetic resonances (NMR) techniques. These enzymes catalyze the reversible isomerization of proline peptide bonds and play numerous biological roles, including aiding in protein folding, signal transduction, and protein trafficking. The reversible nature of this reaction is a critical aspect of this study, since the active enzyme complexes will be directly probed during turnover and the relationship between their inherent movements associated with catalytic motions will be directly determined. Moreover, when combined with mutagenesis, the site-specific roles of both conserved and non-conserved residues to the overall dynamic behavior across a family of enzymes will be assessed. Thus, these studies will determine for the first time whether there are preferences for interactions that lead to dynamic flexibility within enzymes or, conversely, interactions that limit motions. Broader impacts: This research will include the mentoring of both graduate and undergraduates students with a fundamentally different approach to characterizing macromolecules that looks beyond static structural descriptions. The project also includes activities aimed at stimulating undergraduates, especially members of underrepresented groups, to engage in biological research. Furthermore, the study of macromolecular motions on the same timescales as biological processes opens a new window to directly studying conformational events broadly applicable to other biological systems. Thus, inspiring a young generation of researchers to begin asking an entirely new set of questions at the atomic level is a fundamental aspect of this work.

智力优点：酶是必须进行复杂运动才能催化其生物反应的蛋白质。一个相对较新的发现是，酶必须固有的灵活性，并且即使在没有底物的情况下，酶即使在其活性位点进行了运动。从某种意义上说，这些固有的运动已被预先编程为它们的催化功能，但是这种关系是什么是什么以及它们如何在酶家族之间建立联系。尽管基因组时代提供了序列和结构信息，但关于酶动力学的学习很少。此类知识将有助于理解除了决定序列和结构的蛋白质动力学外的进化压力。因此，这项研究的重点是了解酶和蛋白质通常如何通过研究酶家族中的序列，结构，动力学和功能之间的关系而发展为进行动态运动。当前的项目涉及第一次研究，将人类酶家族中同一时间尺度上的动态行为（微毫米尺度）进行比较。使用最近开发的核磁共振（NMR）技术，将比较多种人环蛋白家族成员的动力学行为。这些酶催化了脯氨酸肽键的可逆异构化，并发挥许多生物学作用，包括帮助蛋白质折叠，信号转导和蛋白质运输。该反应的可逆性是本研究的关键方面，因为在营业额期间将直接探测活性酶复合物，并且将直接确定其与催化运动相关的固有运动之间的关系。此外，当与诱变相结合时，将评估保守和非保守残基对整体动态行为的位点特异性作用。因此，这些研究将首次确定相互作用是否有偏好，这些相互作用会导致酶内部的动态灵活性，或者相反，相互作用限制了运动。更广泛的影响：这项研究将包括对研究生和本科生的指导，他们具有从根本上不同的方法来表征大分子的方法，这些方法超出了静态结构描述。该项目还包括旨在刺激大学生，特别是代表性群体不足的成员进行生物学研究的活动。此外，与生物过程相同的时间尺度上的大分子运动的研究为直接研究构象事件的新窗口开辟了一个新的构象事件，广泛适用于其他生物系统。因此，激发年轻一代研究人员开始在原子层提出一组全新的问题是这项工作的基本方面。