Project description and aim Redox proteins have long been identified in nature, where these either effect catalysis via their redox activity or alternatively physically transfer electrons to an acceptor molecule. One of the most crucial questions in investigating such electron transfer between proteins with different functionalities is that of how the electrons are actually transported within the protein matrix. Various efforts have been made to address this question and further characterise this process. To this end we have constructed on a genetic level chimeras of the FMN-containing flavodoxin II from Azotobacter vinelandii and the blue copper protein azurin from Pseudomonas aeruginosa . A diagrammatic representation showing C terminus of flavodoxin linked to the N terminus of azurin by three different length linkers.
Work is underway to purify the three constructs on a large scale.
Optical spectroscopy has already shown that the UV-Vis spectrum of the heterodimer appears to be a hybrid of the two individual protein spectra. Once purified we will proceed with the characterisation of the maquettes, most crucially with respect to the electron transfer properties of the molecules. This work is carried out in conjunction with other workers in our laboratory where the redox centres of the same two proteins have been non-covalently linked with a synthesised organic linker. Other work will include NMR studies to try to determine the sites of interactions of the two proteins in a productive electron transfer complex. It is hoped the work will provide a handle on designing novel redox proteins with desired electron transfer properties.