Multidimensional Femtosecond Correlation Spectroscopic Probe Biomolecules

描述（由申请人提供）：将开发模拟技术，用于预测生物分子对红外和可见光脉冲序列的非线性响应，并将其与各种二级结构基序、结构波动和动力学过程联系起来。这些多维信号提供了动力学事件的飞秒快照，将使用从从头算密度泛函和MD代码获得的多点相关函数来计算和分析。大规模的模拟环境（骨干构象，侧链和溶剂）的波动的振动签名将进行，使用从电子结构计算的单个发色团受到不均匀电场的静电图。 蛋白质折叠途径的特定红外特征，触发温度跳变，嵌入式开关的光异构化，并通过光诱导偶极子将被模拟。本文将研究利用新型光偏振结构的相干时间分辨手性光谱探针。设计策略的脉冲序列在相干。振动和电子光谱学，借鉴类比与核磁共振，将被开发。相干控制算法和灵敏度分析将用于定制脉冲形状，以特定的球状蛋白质中的二级结构基序，解开复杂的光谱，并将它们与特定的结构和动力学过程。酰胺I带的二维振动光谱将用于区分淀粉样蛋白原纤维的平行和反平行β折叠结构。其他的应用将被用于DNA碱基对和光合作用聚集体。氨基酸残基之间的氢键，并与水在多维红外信号的具体签名，将被预测。

DESCRIPTION (provided by applicant): Simulation techniques for predicting the nonlinear response of biomolecules to sequences of infrared and visible pulses, and connecting them to various secondary structure motifs, structure fluctuations and dynamical processes, will be developed. These multidimensional signals, which provide femtosecond snapshots of dynamical events, will be calculated and analyzed, using multipoint correlation functions obtained from ab initio density functional and MD codes. Large scale simulations of vibrational signatures of fluctuations of the environment (backbone conformations, side chains and solvent) will be performed, using an electrostatic map obtained from electronic structure calculations of individual chromophores subjected to a nonuniform electric field. Specific infrared signatures of protein folding pathways, triggered by temperature jump, photoisomerization of an embedded switch, and by optically induced dipoles will be simulated. Coherent time resolved spectroscopic probes of chirality which use novel light polarization configurations will be studied. Design strategies for pulse sequences in coherent.vibrational and electronic spectroscopies, drawing upon the analogy with NMR, will be developed. Coherent control algorithms and sensitivity analysis will be used to tailor pulse shapes to specific secondary structural motifs in globular proteins, disentangle complex spectra and relate them to specific structural and dynamical processes. Two dimensional vibrational spectra of the amide I band will be used to distinguish between parallel and anti-parallel beta sheet structures of Amyloid Fibrils. Other applications will be made to DNA base pairs and photosynthetic aggregates. Specific signatures of hydrogen bonding between amino acid residues, and with water in multidimentional infrared signals, will be predicted.