Allosteric control of loop motions

酶对生命至关重要。了解酶中的原子在它们催化的化学反应中是如何运动的，这对于设计催化新反应的酶是不可或缺的，并将导致生物技术和药物设计领域的进步。本研究旨在通过酶运动的表征及其对催化功能的重要性来影响这些领域。除了对不同科学领域的直接影响外，该项目还将培训博士后科学家掌握最先进的生物物理技术，使他们能够过渡到独立的研究人员。此外，该项目将从代表性不足的群体中招募和培训从事现代生物物理研究的本科生。调节酶的催化活性的机制通常涉及酶在远端（变构）位点和催化（活性）位点之间的结构或动力学扰动的接力。本项目将采用溶液核磁共振（NMR）和计算方法结合生化实验，研究人类酶蛋白酪氨酸磷酸酶1B （PTP1B）的变构调节。这些方法将能够检查PTP1B的动力学，热力学和运动机制。该项目的目标是了解变构变化如何在长分子尺度距离上传递并影响化学反应性。这些目标将通过表征小有机分子在变构位点的结合如何改变活性位点氨基酸的结构和原子柔韧性来实现。此外，我们还将研究PTP1B体内调节其催化活性的天然变弹性位点。这些实验的结合将为PTP1B功能和适用于许多其他重要酶的一般变构模型提供新的见解。

Enzymes are critical for life. Understanding how the atoms in enzymes move during the chemical reactions they catalyze is integral for the design of enzymes that would catalyze novel reactions and would lead to advances in the fields of biotechnology and drug design. This research aims to impact these fields through the characterization of enzyme motions and their importance to catalytic function. In addition to the direct impact on differing scientific areas, this project will result in the training of postdoctoral scientists in state-of-the-art biophysical techniques to enable their transition to independent researchers. Moreover, this project will recruit and train undergraduates, from underrepresented groups, in modern biophysical research.The mechanism by which the catalytic activity of enzymes is regulated often involves the relay of structural or dynamical perturbations in the enzyme between a distant (allosteric) site and the catalytic (active) site. This project will examine the allosteric regulation of the human enzyme, protein tyrosine phosphatase 1B (PTP1B) using solution nuclear magnetic resonance (NMR) and computational methods coupled with biochemical experiments. These methods will enable examination of the kinetics, thermodynamics, and mechanism of motions in PTP1B. The goals of this project will be to understand how allosteric changes can be relayed over long molecular-scale distances and influence chemical reactivity. These goals will be achieved by characterizing how the binding of small, organic molecules at an allosteric site changes the structure and atomic flexibility of amino acids at the active site. In addition, studies will be performed to examine the natural allosteric site in PTP1B that is utilized in vivo to regulate its catalytic activity. This combination of experiments will provide new insight into PTP1B function and into general allosteric models applicable to numerous other important enzymes.