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

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.