Hydride and Hydroxide Intermediates in the Catalytic Turnover of Gas-processing Metalloenzymes
Prof. Dr. Sven T. Stripp
Technische Universität Berlin
Gas-processing metalloenzymes (GPMs) catalyse challenging reactions exploiting abundant transition metal ions like iron, nickel, or molybdenum. Understanding the structure and molecular mechanism of GPMs inspires the design of synthetic catalysts for H2 production, N2 fixation, and the removal of CO2 from the atmosphere.
Based on insight from structural biology and in situ vibrational spectroscopy (1), I will discuss GPMs like hydrogenase (2) and nitrogenase (3). Both enzymes bind specialised iron-sulphur clusters that catalyse proton-coupled electron transfer (PCET) processes. Second and outer coordination sphere effects critically promote metal-hydride species that are key to H2 production with zero electric overpotential and N2 fixation under ambient conditions (4) Similar concepts help understanding the enzymatic conversion of CO2 by carbonic anhydrase that exploits metal-hydroxide species in catalysis(5).
Beyond a microscopic understanding of enzymatic turnover, vibrational spectroscopy on [FeFe]- and [NiFe]-hydrogenase complexes allows demonstrating catalytic coupling with CO2 reduction (6), O2 reduction (7), and electron bifurcation (8).
References
1. S. T. Stripp, ACS Catal. 11, 7845–7862 (2021).
2. H. Tai, S. Hirota, S. T. Stripp, Acc Chem Res. 54, 232–241 (2021).
3. M. Rohde, K. Laun, I. Zebger, S. T. Stripp, O. Einsle, Sci Adv. 7, eabg4474 (2021).
4. S. T. Stripp et al., Chem Rev. 122, 11900–11973 (2022).
5. A. Gomez et al., ChemRxiv. 1–15 (2022).
6. H. M. Dietrich et al., Nature. 607, 823–830 (2022).
7. R. Grinter et al., Nature. 615, 541–547 (2023).
8. A. Katsyv et al., J Am Chem Soc. 145, 5696–5709 (2023).