Dale-Evans, Alister R., Robinson, Martin J., Lloyd-Laney, Henry O. et al. (3 more authors) (2021) A Voltammetric Perspective of Multi-Electron and Proton Transfer in Protein Redox Chemistry::Insights From Computational Analysis of Escherichia coli HypD Fourier Transformed Alternating Current Voltammetry. Frontiers in Chemistry. 672831. ISSN 2296-2646
Abstract
This paper explores the impact of pH on the mechanism of reversible disulfide bond (CysS-SCys) reductive breaking and oxidative formation in Escherichia coli hydrogenase maturation factor HypD, a protein which forms a highly stable adsorbed film on a graphite electrode. To achieve this, low frequency (8.96 Hz) Fourier transformed alternating current voltammetric (FTACV) experimental data was used in combination with modelling approaches based on Butler-Volmer theory with a dual polynomial capacitance model, utilizing an automated two-step fitting process conducted within a Bayesian framework. We previously showed that at pH 6.0 the protein data is best modelled by a redox reaction of two separate, stepwise one-electron, one-proton transfers with slightly “crossed” apparent reduction potentials that incorporate electron and proton transfer terms (E0app2 > E0app1). Remarkably, rather than collapsing to a concerted two-electron redox reaction at more extreme pH, the same two-stepwise one-electron transfer model with E0app2 > E0app1 continues to provide the best fit to FTACV data measured across a proton concentration range from pH 4.0 to pH 9.0. A similar, small level of crossover in reversible potentials is also displayed in overall two-electron transitions in other proteins and enzymes, and this provides access to a small but finite amount of the one electron reduced intermediate state.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2021 Dale-Evans, Robinson, Lloyd-Laney, Gavaghan, Bond and Parkin. |
Dates: |
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Institution: | The University of York |
Academic Units: | The University of York > Faculty of Sciences (York) > Chemistry (York) |
Depositing User: | Pure (York) |
Date Deposited: | 14 Jun 2021 10:40 |
Last Modified: | 21 Jan 2025 17:54 |
Published Version: | https://doi.org/10.3389/fchem.2021.672831 |
Status: | Published |
Refereed: | Yes |
Identification Number: | 10.3389/fchem.2021.672831 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:175175 |