Departmental Seminar

Metal-containing enzymes are ubiquitous, with prominent examples occurring in respiration, photosynthesis, nitrogen fixation, hydrogen activation, to name but a few. Almost half of all enzymes carrying out reduction-oxidation reactions are metalloenzymes. My group’s research focuses on understanding the mechanisms of metalloenzymes through their underlying redox chemistry. In many cases paramagnetic states are involved in mechanistically key locations and our primary tool is electron paramagnetic resonance (EPR) spectroscopy¹.

In the first part of my talk, I will focus on our recent advances^2,3 in understanding the mechanism of complex I, the metalloenzyme that constitutes the entry point of electrons into the respiratory chain that ultimately reduce oxygen to water and power the production of ATP.

In the second part of my talk, I will introduce a new technique that we are developing to study redox-active enzymes and that is applicable to redox-active compounds and catalysts more generally: film-electrochemical EPR.⁴

1.  MM Roessler, E Salvadori, “Principles and applications of EPR spectroscopy in the chemical sciences”, Chemical Society Reviews 2018, 47 (8), 2534-2553, DOI

2.  N Le Breton, JJ Wright, AJY Jones, E Salvadori, HR Bridges, J Hirst, MM Roessler, “Using Hyperfine Electron Paramagnetic Resonance Spectroscopy to Define the Proton-Coupled Electron Transfer Reaction at Fe–S Cluster N2 in Respiratory Complex I”, Journal of the American Chemical Society 2017, 139 (45), 16319-16326, DOI, Spotlight

3.  JJ Wright, G Fedor, J Hirst, MM Roessler, “Using a chimeric respiratory chain and EPR spectroscopy to determine the origin of semiquinone species previously assigned to mitochondrial complex I”, under review

4.  K Abdiaziz, E Salvadori, KP Sokol, E Reisner, MM Roessler, “Protein film electrochemical EPR spectroscopy as a technique to investigate redox reactions in biomolecules”, Chemical Communications 2019, 55 (60), 8840-8843, DOI