TIME RESOLVED AND LOW TEMPERATURE RAMAN INVESTIGATION OF HEME PROTEINS

这项研究将结合两个已建立的资源 实验室，以产生一个完整的动力学研究 络合物中珠蛋白、亚铁血红素和配体之间的相互作用 双分子、血红蛋白。亚稳的血红素暂态物种将是 由配体(02，NO，CO)皮秒光解生成 纳秒脉冲激光光源。这些物种的动态 将在时间尺度上进行探测，从皮秒到毫秒，使用两者 拉曼和吸收技术已经在我们的 实验室。各种珠蛋白及其溶液的作用 将确定双酯复合动力学的条件 用皮秒瞬时吸收光谱。结构性的 共振拉曼光谱的特异性将使我们能够 检查这个复杂系统中的各个分子坐标 低温技术将使我们能够确定能量学 参与近端和远端血红素口袋的松弛 分别在配体光解和重新结合之后。这个 关于经济增长的均衡结构的大量数据 血红蛋白分子，再加上大量的具有 已知的扰动，提供了这样一种预期 可以解释复杂的时间和温度解析数据 在分子的“化学动力学”层面上。这是一个独一无二的 在生物物理学和技术方面的机会和演示 目前在时间分辨拉曼光谱和吸收光谱方面的专业知识 在我们的实验室中可用使这项事业变得卓越 可行。

This study will combine the resources of two established laboratories to produce a complete study of the dynamics of interaction between globin, heme, and ligand in a complex bimolecule, hemoglobin. Metastable heme transient species will be generated via ligand (02, NO, CO) photolysis by picosecond and nanosecond pulsed laser sources. The dynamics of these species will be probed on timescales, from picosecs to millisecs using both Raman and absorption techniques already established in our laboratories. The effects of various globins and solution conditions on geminate recombination kinetics will be determined with picosecond transient absorption spectroscopy. The structural specificity of resonance Raman spectroscopy will allow us to examine individual molecular coordinates in this complex system and cryogenic techniques will allow us to determine the energetics involved in the relaxation of the proximal and distal heme pockets subsequent to ligand photolysis and rebinding respectively. The large body of data concerning the equilibrium structures of the hemoglobin molecules, coupled with the large number of globins with known perturbations, provides for the expectation that it will be possible to interpret complex time and temperature resolved data on a molecular, "chemical dynamics" levels. This is a unique opportunity in biophysics and the technology and demonstrated expertise in time-resolved Raman and absorption spectroscopies now available in our laboratories makes such an undertaking eminently feasible.