Download MendeleyCyanophenylalanine as an Infrared Probe for Iron-Sulfur Cluster Redox State in Multicenter Metalloenzymes.
Duan, Z., Wei, J., Carr, S.B., Ramirez, M., Evans, R.M., Ash, P.A., Rodriguez-Macia, P., Sachdeva, A., Vincent, K.A.(2025) Chembiochem 26: e202500251-e202500251
- PubMed: 40347495
- DOI: https://doi.org/10.1002/cbic.202500251
- Primary Citation of Related Structures:
9GYD, 9GYL, 9GYN, 9GYR, 9GYU, 9GZ0, 9GZ4, 9GZL - PubMed Abstract:
The noncanonical amino acid, para-cyanophenylalanine (CNF), when incorporated into metalloproteins, functions as an infrared spectroscopic probe for the redox state of iron-sulfur clusters, offering a strategy for determining electron occupancy in the electron transport chains of complex metalloenzymes. A redshift of ≈1-2 cm -1 in the nitrile (NC) stretching frequency is observed, following reduction of spinach ferredoxin modified to contain CNF close to its [2Fe-2S] center, and this shift is reversed on re-oxidation. We extend this to CNF positioned near to the proximal [4Fe-4S] cluster of the [FeFe] hydrogenase from Desulfovibrio desulfuricans. In combination with a distal [4Fe-4S] cluster and the [4Fe-4S] cluster of the active site 'H-cluster' ([4Fe-4S] H ), the proximal cluster forms an electron relay connecting the active site to the surface of the protein. Again, a reversible shift in wavenumber for CNF is observed, following cluster reduction in either apo-protein (containing the iron-sulfur clusters but lacking the active site) or holo-protein with intact active site, demonstrating the general applicability of this approach to studying complex metalloenzymes.
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR, UK.
Organizational Affiliation:
