DYNAMICS OF GLUTATHIONE TRANSFERASES

谷胱甘肽转移酶的动力学

• 批准号: 6525524
• 负责人: GORDON S. RULE
• 金额: $ 22.17万
• 依托单位: CARNEGIE-MELLON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-01 至 2005-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6525524
• 关键词: X ray crystallography; catalyst; chemical kinetics; computer simulation; crystallization; enzyme substrate complex; glutathione transferase; intermolecular interaction; isozymes; microcalorimetry; model design /development; molecular dynamics; nuclear magnetic resonance spectroscopy; physical model; protein purification; protein structure function; site directed mutagenesis; structural biology; thermodynamics

DESCRIPTION (provided by applicant): The long range goal of this research program is to determine the molecular basis of the enzymatic mechanism of a class of enzymes called glutathione transferases. These proteins form a family of detoxification enzymes that function by conjugating glutathione to a wide variety of potentially harmful hydrophobic compounds. They have been shown to play an important role in the initiation of tumor growth, as well as in the development of resistance to chemotherapeutic drugs. Collectively, these enzymes show a remarkably broad range of substrate specificities. The goal of this proposal is to determine the relationship between the molecular dynamics and enzyme function for these enzymes. The x-ray derived structures of six classes are currently known. Although the overall fold of these enzymes are similar, each class possesses a distinct molecular architecture which affects both the substrate specificity as well as the enzyme mechanism. For three of these classes (alpha, mu, and pi), a large number of x-ray derived structures of these proteins have been determined. In some cases, these structures show considerable change in the conformation of the enzyme due to ligand binding. In other cases, substrate binding causes little change in structure. Since all of these studies have been performed in the crystalline lattice, the extent and importance of ligand induced changes on the structure and dynamics of these enzymes in solution is unknown. A more comprehensive understanding of these enzymes will be useful in the development of more useful chemotherapeutics. The specific aims of this proposal are to investigate substrate induced changes in the dynamics of human class mu, pi, alpha, and theta enzymes by NMR spectroscopy. The first hypothesis to be tested is that molecular dynamics of the backbone plays an important role in the enzymatic mechanism of these enzymes by gating substrate accessibility and product release. The dynamic properties of the backbone atoms in these enzymes in the presence and absence of various substrates and products will be investigated with measurements of amide exchange kinetics, residual dipolar coupling, chemical exchange, and 15N nuclear relaxation. The second hypothesis to be tested is that the dynamic properties of side-chain residues play an important role in the recognition of different substrates by the same enzyme. Side chain dynamics of wild-type and mutant proteins will be characterized by '3C, 2H, and 19F nuclear spin relaxation.

描述（由申请人提供）：这项研究的远距离目标 程序是确定A的酶促机制的分子基础 酶类称为谷胱甘肽转移酶。这些蛋白质形成家庭 通过将谷胱甘肽连接到宽的排毒酶 各种潜在有害的疏水化合物。他们被证明 在肿瘤生长的开始以及 对化学治疗药物的抗性发展。总的来说，这些 酶显示出广泛的底物特异性。 该提议的目的是确定 这些酶的分子动力学和酶功能。 X射线得出 目前已知六个课程的结构。虽然总体折叠 这些酶是相似的，每个类都有一个独特的分子 影响底物特异性和酶的结构 机制。对于其中三个班级（Alpha，Mu和Pi），大量 已经确定了这些蛋白质的X射线衍生结构。在某些情况下， 这些结构在应得的酶的构象上显示出很大的变化 进行配体结合。在其他情况下，底物结合几乎没有变化 结构。由于所有这些研究都在结晶中进行 晶格，配体诱发结构变化的程度和重要性 这些酶在溶液中的动力学尚不清楚。更全面 对这些酶的理解将有助于开发更有用 化学治疗学。 该提案的具体目的是调查底物诱导的变化 在人类类Mu，Pi，Alpha和Theta酶的动力学中 光谱法。要测试的第一个假设是 骨干在这些酶机制中起重要作用 通过门控底物的可访问性和产品释放来酶。动态 在存在和不存在的情况下，这些酶中主链原子的特性 各种底物和产品的测量 酰胺交换动力学，残留偶极耦合，化学交换和15N 核放松。要测试的第二个假设是动态 侧链残留物的特性在识别中起着重要作用 不同的底物通过相同的酶。野生型的侧链动力学和 突变蛋白将以'3C，2H和19F核自旋为特征 松弛。