CAREER: Determination of enzyme mechanisms using new kinetic isotope effect approaches

通过这一职业奖，生命过程化学项目正在支持纽约州立大学布法罗大学的安德鲁·穆尔金博士开发研究酶反应机制的新方法。这项研究的目的是确定两种酶的过渡态结构，这两种酶催化反应的机制尚未解决。为了实现这一目标，默金博士开发了一种基于二维核磁共振光谱学的测量动力学同位素效应的方法，该方法比以前的方法具有更高的灵敏度和精确度。过渡态模型将通过将理论动力学同位素效应与实验测量的同位素效应相匹配来构建。当一个分子发生反应并达到过渡态时，反应或经历几何或静电变化的原子在被较重的同位素取代时会产生不同的速率。这种动力学同位素效应提供了在机构的限速步骤中可通过实验获得的底物的图像。从这一奖项开发的技术应该会引起广大科学家的兴趣，他们依靠动力学同位素效应来研究各种过程，包括新疗法的设计。该计划还旨在鼓励年轻人接受生物化学和相关科学方面的培训。为了激发年轻人的教育兴趣，将通过在中学和大学实验室进行的信息丰富的动手、基于探究的实验，向大布法罗学校的K-12学生，包括代表不足的年轻人，提供酶的介绍。在大学一级，过渡态抑制剂的设计和动力学同位素效应的测量将被纳入本科生和研究生的化学课程。

With this CAREER award, the Chemistry of Life Processes Program is supporting Dr. Andrew Murkin of the University at Buffalo, The State University of New York, in the development of new methods for studying the mechanisms of enzymatic reactions. The objective of this research is to determine the transition state structures of two enzymes that catalyze reactions with unresolved mechanisms. To reach this goal, Dr. Murkin developed a method for measuring kinetic isotope effects based on two-dimentional NMR spectroscopy that delivers better sensitivity and precision than previous methods. Transition state models will be constructed by matching the theoretical kinetic isotope effects obtained computationally to those measured experimentally.When a molecule undergoes a reaction and reaches the transition state, the atoms that react or experience geometric or electrostatic changes exert differences in rates when substituted with heavier isotopes. Such kinetic isotope effects provide an experimentally accessible picture of the substrate during the rate-limiting step in a mechanism. The techniques developed from this award should be of interest to a wide audience of scientists who depend on kinetic isotope effects to study a variety of processes, including the design of new therapies. This program is also designed to encourage youth to pursue training in biochemistry and related sciences. To stimulate educational interest among youth, an introduction to enzymes will be provided to K-12 students in greater-Buffalo schools, including underrepresented youths, through informative hands-on, inquiry-based experiments conducted in middle schools and in a university laboratory. At the university level, the design of transition state inhibitors and measurement of kinetic isotope effects will be integrated into undergraduate and graduate chemistry courses.