COUPLING NETWORKS AND SIDE-CHAIN DYNAMICS IN PROTEINS

蛋白质中的偶联网络和侧链动力学

• 批准号: 7433472
• 负责人: Andrew L Lee
• 金额: $ 3.66万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-01 至 2009-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7433472
• 关键词: Active Sites; Address; Attention; Base Sequence; Biochemical; Biological; Biological Assay; Biological Models; Catalysis; Chemicals; Communication; Complex; Core Protein; Coupled; Coupling; Data; Detection; Development; Disruption; Dissection; Distal; Drug resistance; Enzymes; Event; Evolution; Fluorescence; Free Energy; Goals; Individual; Kinetics; Ligands; Maps; Marshal; Measurement; Mediating; Methods; Molecular; Monitor; Motion; Mutagenesis; Mutation; Pathway interactions; Pattern; Positioning Attribute; Predictive Value; Property; Proteins; Range; Regulation; Relative (related person); Relaxation; Research; Research Personnel; Resolution; Role; Serine Proteinase Inhibitors; Side; Signal Transduction; Site; Solutions; Specific qualifier value; Structure; Substrate Specificity; Surface; Testing; Thermodynamics; Variant; Vertebral column; Work; base; carbene; density; design; desire; engineering design; experience; globular protein; interest; intermolecular interaction; molecular recognition; mutant; novel strategies; programs; receptor; research study; response; transmission process

Biological signals are transmitted via molecular communication. While a great deal of attention has been directed at characterizing the structural basis of intermolecular communication in protein complexes, little is known about how signals propagate across distances within individual globular proteins or domains. Such events occur in allosteric proteins, components of molecular recognition, ligand receptors, and enzymes. Site-site communication across distances is therefore a fundamental feature of proteins. Atomic resolution studies of intramolecular communication are needed to explain sequence-based modulations of protein activity, substrate specificity, ligand regulation, and distal mutations conferring drug resistance. The influence of distal residues on a protein's active site will be particularly valuable for protein design. The research in this proposal seeks to determine the mechanistic basis for site-site communication using a combination of biophysical and biochemical approaches. Three specific aims address the central hypothesis for this proposal - that side-chain dynamics mediate long-range communication in proteins. Experiments will be carried out on eglin c, a small serine protease inhibitor possessing favorable properties to aid development of the proposed novel approaches. Detection of long-range, pair-wise communication, or "coupling", will be made from extensive thermodynamic double-mutant cycle analysis. Couplin_ networks will also be mapped through propagated changes in side-chain dynamics, as observed from NMR H spin relaxation measurements in solution. To test mechanisms of signal propagation and the evolution of communication networks from a design perspective, "on-pathway" mutations will be made in order to modulate communication between sites. The functional significance of communication pathways that connect with the active site inhibitory loop will be assessed from a kinetics-based inhibition assay. The mapping of entire coupling networks through the approach presented is general and should be applicable to other proteins and protein complexes.

生物信号通过分子通信进行传输。虽然已经引起了极大的关注 旨在描述蛋白质复合体中分子间通信的结构基础，Little is 已知信号如何在单个球状蛋白质或结构域内跨距离传播。是这样的 这些事件发生在变构蛋白、分子识别组件、配体受体和酶中。 因此，远距离的点对点通信是蛋白质的一个基本特征。原子分辨率 需要研究分子内通讯来解释蛋白质的基于序列的调制 活性、底物专一性、配体调节和导致耐药的远端突变。这个 末端残基对蛋白质活性部位的影响对蛋白质设计具有特别重要的意义。这个 该建议中的研究试图确定站点到站点通信的机制基础，使用 生物物理和生化方法的结合。三个具体目标解决了中心假设 对于这一提议--侧链动力学调节蛋白质中的长距离通讯。实验将会 对Eglin c进行研究，Eglin c是一种小的丝氨酸蛋白酶抑制剂，具有促进发育的良好特性 所提议的新方法。将检测到远程、成对通信或“耦合” 由广泛的热力学双突变循环分析制成。Couplin_Networks也将被映射 通过从核磁共振氢自旋弛豫测量中观察到的侧链动力学的传播变化 在溶液中。为了测试信号传播机制和通信网络的演变 从设计的角度来看，“在路径上”会做出突变，以调节站点之间的交流。 连接活性部位抑制环的通讯通路的功能意义将 通过基于动力学的抑制试验进行评估。整个耦合网络的映射通过 该方法具有一定的通用性，适用于其他蛋白质和蛋白质复合体。