Overseas Travel to Caltech - Probing of protein dynamics and electron transfer with transition metal chromophores

玛丽皇后学院、伦敦大学和加州研究所的研究小组对金属蛋白的超快弛豫和电子转移（ET）动力学进行了联合研究。简而言之，蛋白质（azurins）是由含有铼的发色体衍生的，这些发色体附着在蛋白质表面特定位置的组氨酸基团上。激光脉冲激发Re发色团触发周围溶剂分子和Re结合位点附近的肽单元的重组（松弛）。在一些蛋白质中，分子内的电子转移也会被触发。这两个过程的动力学，然后通过结合几种最先进的时间分辨激光光谱技术进行研究。这项研究对我们了解氧化还原蛋白在生物系统中的功能以及基于蛋白质的分子装置的可能发展具有深远的影响。在这项联合研究过程中，伦敦小组研究了加州理工学院提供的衍生蛋白的皮秒时间分辨红外和荧光光谱，而加州理工学院则进行了可见光谱区域的补充研究和蛋白质结构的测定。理解这些复杂的现象是具有挑战性的，需要结合两组的动力学数据以及它们在解释和发展机制模型上的密切互动。为了促进这项研究和规划未来的活动，建议对加州理工学院进行短期访问。

A joint research is carried out between the groups at Queen Mary, University of London and California Institute on ultrafast relaxation and electron-transfer (ET) dynamics of metalloproteins. In brief, proteins (azurins) are derivatized by rhenium-containing chromophors which are attached to a histidine group at specific locations of the protein surface. Laser-pulse excitation of the Re chromophore triggers restructuring (relaxation) of the surrounding solvent molecules and the peptide units in the vicinity of the Re binding site. In some proteins, an intramolecular electron transfer is triggered as well. Dynamics of both processes are then studied by combining several state-of-the-art time-resolved laser spectroscopic techniques. This research has far-reaching consequences for our understanding of functioning of redox proteins in biological systems and for possible development of molecular devices based on proteins. In the course of this joint research, picosecond time-resolved infrared and fluorescence spectra of derivatized proteins supplied from Caltech are studied by the London group, while complementary studies in the visible spectral region and determination of protein structures are performed at Caltech. Understanding of these complex phenomena is challenging and requires combining kinetic data from both groups and their close interaction on interpretation and development of mechanistic models. To foster this research and plan future activities, a short visit to Caltech is proposed.