Protein Film Electrochemistry and Spectroscopy.
Techniques of dynamic electrochemistry, such as cyclic voltammetry, are powerful tools for characterising redox proteins and enzymes. Electron transfer and any associated chemical events are visualised in real-time by the flow of electrical current when electrons are exchanged between a protein and an electrode of known and variable potential. Using this technique our research resolves fundamental properties of redox-active proteins. The information allows us to understand how biochemical properties are tuned to match the cellular role of the protein, and, to inform protein engineering to inspire advances in biotechnology for solar fuels.
Most of our electrochemistry is performed with the protein of interest adsorbed as an electroactive (sub-)monolayer film on an electrode surface; an approach known as protein film electrochemistry. While studying enzyme catalysis we rapidly rotate the enzyme coated electrode during measurements. These strategies remove contributions to the voltammetry from sluggish protein and substrate diffusion to provide high-resolution, quantitative insight into both thermodynamic and kinetic properties of the adsorbed enzyme. We are able to quantify reduction potentials, binding affinities for protons (ligands) and define rates of ligand binding, catalysis and inhibition.
To enhance the information from our experiments we can also perform electrochemistry with simultaneous spectroscopy of the electroactive material. Our spectroelectrochemical cells allow electronic absorbance, Fourier transform infrared spectroscopy (FTIR) and magnetic circular dichroism (MCD) spectroscopies.
Selected Publications
J. Am. Chem. Soc. 2022
2. Heme Ligation and Redox Chemistry in Two Bacterial Thiosulfate Dehydrogenase (TsdA) Enzymes
4. Comparative Structure-Potentio-Spectroscopy of the Shewanella Outer Membrane Multiheme Cytochromes.
5. Catalytic Protein Film Electrochemistry Provides a Direct Measure of the Tetrathionate/Thiosulfate Reduction Potential.
6. Resolution of Key Roles for the Distal Pocket Histidine in Cytochrome c Nitrite Reductases.