INFRARED STUDY OF OXIDASE DYNAMICS

时间分辨红外（TRIR）研究蛋白质动力学的所有时间尺度 提出了从亚皮秒到秒的范围。 主要目标是 研究是来自哺乳动物和细菌的细胞色素氧化酶。 一些工作的 建议使用肌红蛋白和血红蛋白来确定技术可行性， 来模拟更复杂的氧化酶。 长期目标是 了解氧化酶的结构细节和功能动力学， 地球上所有的有氧生物都依赖于此。 技术目标是 开发新的和普遍适用的方法来研究蛋白质 动力学，基于对结构特征的红外观测 其他光谱探测器看不到的物质。 一套TRIR 技术将被使用：亚皮秒到 纳秒动态;从纳秒到纳秒动态的实时TRIR 秒;直接测定用时间分辨红外线线性二色性 红外线活性结构和电子 偶极子和步进扫描时间分辨FAIR用于观察瞬态 在整个红外光谱范围内的现象。 这些研究报告将 在适当的情况下辅以瞬态电子光谱，时间- 分辨磁圆二色性和时间分辨共振拉曼 调查事务所 具体研究包括：（1）TRIR 结扎动力学研究，包括 血红素键配体的光解/重组， 光解离，与非血红素金属的结合，以及动力学的依赖性 空间和电子因素。 结果将详细说明 理解O2位点的连接和空间现象 activation. (2)内源性蛋白质IR发色团的TRIR研究， 包括氨基酸侧链、肽骨架和假体 组 结果将阐明蛋白质结构的响应 和构象的连接和氧化还原扰动。 (3)时间分辨 红外线性二色性，结合上述（1）和（2）研究， 旨在确定特定的结构重新取向， 短时间尺度的动态。

Time-resolved infrared (TRIR) studies of protein dynamics on all timescales from subpicosecond to seconds are proposed. The primary targets of this study are cytochrome oxidases from mammals and bacteria. Some work on myoglobin and hemoglobin is suggested to establish technical feasibility or to model the more complicated oxidases. The long-term goal is to understand in structural detail the functional dynamics of the oxidases, upon which all aerobic life on earth depends. A technical objective is to develop new and generally applicable approaches to the study of protein dynamics, based upon the observation by infrared of structural features that are invisible to other spectroscopic probes. A suite of TRIR techniques will be used: optical delay methods for subpicosecond to nanosecond dynamics; real-time TRIR for dynamics from nanoseconds to seconds; time-resolved infrared linear dichroism for direct determination of the relative orientation of infrared-active structures and electronic dipoles, and step-scan time-resolved FAIR for observation of transient phenomena over the entire infrared spectrum. These studies will be supplemented where appropriate by transient electronic spectroscopy, time- resolved magnetic circular dichroism, and time-resolved resonance Raman investigations. Specific studies to be performed include: (1) TRIR investigation of ligation dynamics, including photodissociation/recombination of heme-bond ligands, fate of ligands after photodissociation, binding to nonheme metals, and dependence of dynamics upon steric and electronic factors. The result will be detailed understanding of ligation and steric phenomena at the site of O2 activation. (2) TRIR studies of endogenous protein IR chromophores, including amino acid side chains, the peptide backbone and prosthetic groups. The results will elucidate the response of the protein structure and conformation to ligation and redox perturbations. (3) Time-resolved infrared linear dichroism, studied in connection with (1) and (2) above, aimed at determining specific structural reorientations which occur during the short-timescale dynamics.