In Fall 2022, R. David Britt was awarded the ACS Alfred Bader Award in Bioinorganic Chemistry for pioneering pulse electron paramagnetic resonance (EPR) spectroscopy of the photosystem II oxygen-evolving complex, plus the advanced EPR spectroscopic characterization of numerous and varied key metalloenzymes and catalysts.
This literature discussion covers his work to uncover the bioassembly of the H-cluster of the enzyme [FeFe] Hydrogenase by reading the paper “A [4Fe–4S]-Fe(CO)(CN)-l-cysteine intermediate is the first organometallic precursor in [FeFe] hydrogenase H-cluster bioassembly,” (Nat. Chem. 2018, 10, 555-560).
Upon completion of this literature discussion, a students should be able to:
- Describe the structure and function of [FeFe] hydrogenase enzymes
- Determine geometry, d-electron count, and d-orbital splitting diagrams for iron atoms in high and low spin configurations
- Explain antiferromagnetism and rationalize spin states of [4Fe-4S] clusters
- Predict spin states of coupled paramagnetic species
- Describe the information that is provided by EPR spectroscopy
- Discuss how EPR spectroscopy was used to confirm the presence of an organometallic intermediate in the HydG protein
We have not used this literature discussion in class yet, but would be useful following instruction on ligand field theory to see relevance and application in understanding bioinorganic systems. The assignment does not require a deep dive into "how EPR works" but focuses more on what the variety of EPR-related techniques can tell us.