VIBRATIONAL OPTICAL ACTIVITY IN BIOLOGICAL MOLECULES

振动光学活性（VOA），其由拉曼光学性质组成。 活性（罗阿）和振动圆二色性（VCD），将是 沿着工具性、解释性和理论性路线前进， 目的是改进现有的测定方法， 生物分子的溶液相构象。 多通道罗阿 光谱仪将通过更换OMA 2计算机控制台进行升级 通过OMA III控制台， 电荷耦合器件（CCD）检测器，以实现更大的仪器 可靠性和光谱灵敏度。 新的工具性方法， 罗阿的测量，最近在我们的 实验室，并被称为散射圆偏振（SCP）罗阿 和双圆偏振（DCP）罗阿，将被利用为他们的 与传统的罗阿测量相比，提高了效率和稳定性 技术，称为入射圆偏振（ICP）罗阿。 测量最初将集中在已经 在溶液中表现出强的罗阿光谱，并将继续向类似的 更复杂的分子。 计量方法 还将探索共振罗阿。 这种测量是有意义的 因为它们的结构选择性， SCP和ICP罗阿之间的差异预计将在 共振拉曼条件。 VOA技术在生物医学研究中的应用 生物分子构象将通过测量VCD来突出显示 使用锡拉丘兹现有的三台VCD光谱仪中的任何一台 大学 待测样品包括氨基酸，简单 肽，甘油醛，儿茶酚胺神经递质分子， 三足肽、叠氮高铁血红蛋白和叠氮高铁肌红蛋白，以及 另外选择的蛋白质、胺、醇、糖和相关的 分子。 VCD光谱将通过使用或扩展 环电流强度机制的规则或通过应用 耦合振荡器强度机制 将特别注意 专门研究VCD的灵敏度，通过环电流机制， 分子内氢键的存在，其中一些涉及 只有弱形式的分子内缔合，如氧孤对电子 脂肪族碳氢相互作用。 电声耦合 VCD和罗阿强度的表达以及与实验的比较 结果 重点将放在将下列结果联系起来： 基本VOA模型和解释方法的计算， 如VCD的环电流机制。 模型二醇和氨基 醇、丙氨酸和氘代甘氨酸将作为初始靶点 用于计算。 与往年一样，本次会议的重点是 研究将在氨基酸和肽分子;然而，研究 对其他类型的分子，这是非常适合的目标， 该计划将作为对美国之音更灵活的方法的一部分 research.

Vibrational optical activity (VOA), which is comprised of Raman optical activity (ROA) and vibrational circular dichroism (VCD), will be advanced along instrumental, interpretational and theoretical lines with the aim of improving existing methods for the determination of the solution-phase conformations of biomolecules. A multichannel ROA spectrometer will be upgraded by replacing the OMA 2 computer console with an OMA III console and adding the capability of a multichannel charge coupled device (CCD) detector to achieve greater instrumental reliability and spectral sensitivity. New instrumental approaches to the measurement of ROA, recently conceived and devised in our laboratory, and referred to as scattered circular polarization (SCP) ROA and dual circular polarization (DCP) ROA, will be exploited for their enhanced efficiency and stability over conventional ROA measurement techniques, termed incident circular polarization (ICP) ROA. Measurements will focus initially on molecules that have already exhibited strong ROA spectra in solution and will proceed toward similar molecules of greater complexity. Approaches to the measurement of resonance ROA will also be explored. Such measurements are of interest because of their structural selectivity and because theoretical differences between SCP and ICP ROA are predicted to be enhanced under resonance Raman conditions. Applications of VOA to the study of biomolecular conformations will be highlighted by measurements of VCD using any one of three existing VCD spectrometers at Syracuse University. Samples to be measured include amino acids, simple peptides, glyceraldehyde, catecholamine neurotransmitter molecules, tripodal peptides, azidomethemoglobin and azidometmyoglobin, and additional selected proteins, amines, alcohols, sugars and related molecules. The VCD spectra will be interpreted by using or extending the rules of the ring current intensity mechanism or by applying the coupled oscillator intensity mechanism. Particular attention will be devoted to the sensitivity of VCD, via the ring current mechanism, to the presence of intramolecular hydrogen bonds, some of which involve only weak forms of intramolecular association such as oxygen lone pair to aliphatic carbon hydrogen interactions. Vibronic coupling expressions of VCD and ROA intensities and comparison to experimental results. Emphasis will be placed on relating the results of calculations to elementary VOA models and interpretational approaches, such as the ring current mechanism of VCD. Model diols and amino alcohols, alanine and deuteriated glycine will serve as initial targets for calculations. As in previous years, the primary focus of this research will be on amino acids and peptide molecules; however, research on other types of molecules that are well suited to the goals of this program will be pursued as part of a more flexible approach to VOA research.