Synthesis and Study of Minimal Protein Folding Models: Molecular Torsion Balance

最小蛋白质折叠模型的合成与研究：分子扭转平衡

• 批准号: 7413629
• 负责人: CRAIG S WILCOX
• 金额: $ 27.02万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-05-01 至 2011-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7413629
• 关键词: Address; Affect; Affinity; Amino Acids; Attention; Behavior; Benchmarking; Binding; Binding Sites; Biochemistry; Biological; Biological Models; Biological Phenomena; Catalysis; Chemicals; Communities; Competitive Binding; Complex; Computing Methodologies; Controlled Study; Data; Dependence; Drug Design; Drug Receptors; Enzymes; Equilibrium; Event; Free Energy; Halogens; Heart; Hydrogen Bonding; Hydrophobic Interactions; Hydrophobic Surfaces; Hydrophobicity; Indium; Individual; Ionic Strengths; Knowledge; Measures; Mediating; Methods; Molecular; Molecular Conformation; Molecular Models; Object Attachment; Pharmaceutical Preparations; Principal Investigator; Proteins; Relative (related person); Reporting; Risk; Science; Scientist; Side; Sodium Chloride; Solvents; Structure; Surface; System; Temperature; Testing; Theoretical model; Thermodynamics; Torsion; Water; Week; aqueous; behavior influence; concept; design; functional group; insight; interest; macromolecule; mimetics; model design; novel; programs; protein folding; receptor binding; research study; size; small molecule; theories; tool

DESCRIPTION (provided by applicant): Testing and improvement in our understanding of the molecular forces that influence biological phenomena (events including protein folding, protein-protein recognition, drug-receptor binding, and enzyme catalysis) require precise observations in well-controlled experiments. We developed a tool - the 'molecular torsion balance' - for measuring the relative energies of two well separated thermodynamic states which differ only in their conformation. These precision molecular tools can reliably measure differential energy effects on conformation as small as 0.05 kcal/mol. We propose to use these molecules in aqueous systems and to acquire quantitative data relevant to five important binding motifs that are central elements in theories of protein stability. The subprojects are designed to provide data directly relevant to understanding biological recognition (folding and binding) and useful for testing current biocomputational methods and theories. We will investigate: 1) The effects of salt bridges on conformational stability. Our experiments will provide quantitative comparisons of the strength of solvent-exposed salt bridges most common in biological molecules, and on the effects of ionic strength and temperature on these effects. 2) Hydrophobic binding and the effect of non-polar surfaces on water-mediated conformational stability. The Lum-Chandler-Weeks (LCW) theory of hydrophobicity makes intriguing predictions on how hydrophobicity changes with the sizes of alkyl surfaces. We seek to verify this prediction and quantify the differences. 3) The effects of halogens and the 'halogen bond' on conformation stability in water. The introduction of halogens into drug molecules is reported to change binding site affinities. 4) Neighboring group effects on hydrophobic interactions. How do nearby functional groups influence the 'stickiness' of hydrophobic surfaces? Is there an effect on the structure of water that can change the excess free energy at hydrophobic-water interfaces? 5) A beta-turn mimetic molecular torsion balance. A moderate risk -high impact subproject will allow direct comparisons of the energy of pair-wise amino acid interactions in anti-parallel orientation and the effects of amino acid changes on short beta-strand stability. Knowledge gained in these experimental studies will be available for testing current computational methods and theories of biological recognition and in identifying guiding principles for design of biologically active agents.

描述（由申请人提供）：测试和改进我们对影响生物现象（包括蛋白质折叠、蛋白质-蛋白质识别、药物-受体结合和酶催化的事件）的分子力的理解需要在良好控制的实验中进行精确观察。我们开发了一种工具-"分子扭转天平"-用于测量两个分离良好的热力学状态的相对能量，这两个状态仅在构象上不同。这些精密的分子工具可以可靠地测量差能对构象的影响小至0.05千卡/摩尔。我们建议使用这些分子在水溶液中的系统，并获得定量的数据有关的五个重要的结合基序，在理论上的蛋白质稳定性的核心要素。这些子项目旨在提供与理解生物识别（折叠和结合）直接相关的数据，并用于测试当前的生物计算方法和理论。我们将研究：1）盐桥对构象稳定性的影响。我们的实验将提供定量比较的溶剂暴露的盐桥最常见的生物分子的强度，离子强度和温度对这些效果的影响。2)疏水结合和非极性表面对水介导构象稳定性的影响。Lum-Chandler-Weeks（LCW）疏水性理论对疏水性如何随烷基表面尺寸变化做出了有趣的预测。我们试图验证这一预测并量化差异。3)卤素和“卤键”对水中构象稳定性的影响。据报道，将卤素引入药物分子中会改变结合位点的亲和力。4)相邻基团对疏水相互作用的影响。附近的官能团如何影响疏水表面的"粘性"？水的结构是否会影响疏水-水界面的过量自由能？5)一种β转角模拟分子扭转天平。中等风险-高影响子项目将允许直接比较反向平行方向的成对氨基酸相互作用的能量和氨基酸变化对短β链稳定性的影响。在这些实验研究中获得的知识将可用于测试当前的计算方法和生物识别理论，并确定设计生物活性剂的指导原则。