Residue Scale Characterization of Protein Structure Fluctuations

蛋白质结构波动的残留规模表征

• 批准号: 6706158
• 负责人: ROBIN Main HOCHSTRASSER
• 金额: $ 10.94万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6706158
• 关键词: biomaterials; calmodulin; cytochrome c; electric field; electrical property; electron transport; electronic spectra; gel; hydrogen bond; infrared spectrometry; ionic bond; molecular dynamics; photolysis; protein protein interaction; protein structure function; quantum chemistry; time resolved data; trehalose; vibration

Real time measurements of energy and angular fluctuations in peptides and proteins using ultrafast optical, stimulated IR echoes, 2D IR and single molecule spectroscopy are proposed to examine interactions and correlations between vibrational modes and their surroundings for isotopic selections of peptides and proteins. Time correlation functions for amide-I, amide-II, CH3 and amide-A groups selected by carbon, oxygen and deuterium isotopic replacement will be measured and modeled. The influence of electrostatics, solvent interactions and structural heterogeniety on delocalization of vibrational energy in peptides will be examined. IR photon echoes and dynamic 2D IR will allow characterization of the solvent related energy fluctuations of selected pieces of alpha helices, and evaluation of effects of charged residues and polar solvents from the vibrational dynamics, and fast hydrogen bond dissociation dynamics of water molecules (HDO) from ions nearby to proteins. The dynamics of cytochrome c at equilibrium and following CO photolysis will be examined by 2D IR of 18O, 13C and deuterium labeled residues to determine the fluctuations in the Met (80) residue and Phe (82). Infrared transitions of optically excited aggregates will be examined and theoretical models for amide IR spectra in secondary structures will be developed. Single molecule experiments based on spectra, lifetime and photon arrival time distributions will address equilibrium fluctuations of the glass and hydrogel encapsulated calcium calmodulin peptide complex via Nile Red fluorecence quenching, LH2 complexes, trehalose protein interactions and the distributions of rates of energy transfer in donor and acceptor labeled peptides immobilized in glasses and gels near the glass transitions.

提议使用超快的光学，刺激的IR回波，2D IR和单分子光谱检查肽和蛋白质中能量和角波动的实时测量，以检查振动模式及其周围环境之间的相互作用和相关性，以便对肽和蛋白质的同位素选择。将测量和建模用于碳，氧和同位素替代的酰胺-I，酰胺-II，CH3和酰胺-A组的时间相关函数。将研究静电，溶剂相互作用和结构异质化对肽振动能量的振动能量的影响。 IR光子回声和动态2D IR将允许表征所选α螺旋的溶剂相关能​​量波动，并评估带电残基和极性的效果 来自振动动力学的溶剂，以及从附近离子到蛋白质的水分子（HDO）的快速氢键解离动力学。在平衡和CO光解之后的细胞色素C的动力学将通过18O，13C和氘标记的残基进行检查，以确定MET（80）残基和PHE中的波动（82）。将检查光学激发骨料的红外线转变，并将开发二级结构中酰胺红外光谱的理论模型。基于光谱，寿命和光子到达时间分布的单分子实验将通过尼罗红色荧光淬灭，LH2复合物，沙洛斯蛋白质相互作用以及供体转移速率的含量淬灭，以解决玻璃和水凝胶封装钙和水凝胶封装的平衡波动。受体将固定在玻璃过渡附近的玻璃和凝胶中的肽标记。