STRUCTURE AND FUNCTION IN ENZYME CATALYSIS

酶催化的结构和功能

• 批准号: 2178630
• 负责人: JEREMY R KNOWLES
• 金额: $ 14.89万
• 依托单位: HARVARD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-07-01 至 1995-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2178630
• 关键词: X ray crystallography; acidity /alkalinity; chemical binding; chemical group; chemical kinetics; conformation; enzyme mechanism; enzyme structure; enzyme substrate; intermolecular interaction; ionization; molecular genetics; mutant; nuclear magnetic resonance spectroscopy; point mutation; polymerase chain reaction; protein engineering; protein sequence; site directed mutagenesis; suppressor mutations; thermodynamics; thermostability; triose phosphate isomerase

The goal of this proposal is to gain a deeper understanding of enzyme catalysis. Our aims are:(a), to see why particular functional groups in enzymes are ideal for particular catalytic tasks:(b), to recognize the usefulness of particular structural motifs; (c), to be able to predict the kinetic consequences of small structural changes; and (d), to see if the kinetic properties of enzymes have been refined for each metabolic niche. We shall continue to exploit triosephosphate isomerase, which is a splendid test-bedford the evaluation of important elements of enzyme catalysis. Site-directed changes will be use d to probe particular enzyme features and functionalities, and the technique of random mutagenesis will be further developed to explore the nature of the sequence 'landscape' in the generation of catalytic potency. In these pursuits, answers to the following questions will be sought: Do enzymes use bidentate bases and acids to catalyze proton shifts merely by side-chain rotation? Can we test recent theoretical statements about the importance of charges that are relatively remote from the active site? How does an alpha-helix fine-tune the pKa value of an ionizing group, or affect the strength of substrate binding? What is the movement of 1 A worth kinetic terms? Can equivalent rate accelerations be achieved wit a different set of catalytic groups? Are enzymes from organisms adapted to lave a t-1.6oC or + 105oC predictably different? Answers to these and other questions will provide a firmer basis from which the catalytic activity of enzymes can become a predictive science.

该提案的目标是更深入地了解酶 催化。我们的目标是：(a)，了解为什么特定的官能团 酶是特定催化任务的理想选择：(b)、识别 特定结构主题的有用性； (c) 能够预测 微小结构变化的动力学后果； (d)，看看是否 酶的动力学特性已针对每个代谢生态位进行了细化。 我们将继续开发磷酸三糖异构酶，这是一种出色的酶 test-bedford 酶催化重要元素的评估。 定点改变将用于探测特定的酶特征和 功能和随机诱变技术将得到进一步发展 开发的目的是探索序列“景观”的本质 产生催化效力。在这些追求中，答案 将寻求以下问题：酶是否使用双齿碱基？ 酸仅通过侧链旋转来催化质子转移？我们可以测试吗 最近关于电荷重要性的理论陈述 距离活动地点相对较远？ α螺旋如何微调 电离基团的 pKa 值，或影响底物的强度 绑定？ 1 A 值的变动动力学项是什么？可以等效 使用一组不同的催化基团可以实现速率加速吗？是 来自适应 t-1.6oC 或 + 105oC 可预测的生物体的酶 不同的？这些问题和其他问题的答案将为我们提供更坚实的基础 酶的催化活性可以从中预测 科学。