1
|
Brocks C, Das CK, Duan J, Yadav S, Apfel UP, Ghosh S, Hofmann E, Winkler M, Engelbrecht V, Schäfer LV, Happe T. A Dynamic Water Channel Affects O 2 Stability in [FeFe]-Hydrogenases. ChemSusChem 2024; 17:e202301365. [PMID: 37830175 DOI: 10.1002/cssc.202301365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/05/2023] [Accepted: 10/11/2023] [Indexed: 10/14/2023]
Abstract
[FeFe]-hydrogenases are capable of reducing protons at a high rate. However, molecular oxygen (O2 ) induces the degradation of their catalytic cofactor, the H-cluster, which consists of a cubane [4Fe4S] subcluster (4FeH ) and a unique diiron moiety (2FeH ). Previous attempts to prevent O2 -induced damage have focused on enhancing the protein's sieving effect for O2 by blocking the hydrophobic gas channels that connect the protein surface and the 2FeH . In this study, we aimed to block an O2 diffusion pathway and shield 4FeH instead. Molecular dynamics (MD) simulations identified a novel water channel (WH ) surrounding the H-cluster. As this hydrophilic path may be accessible for O2 molecules we applied site-directed mutagenesis targeting amino acids along WH in proximity to 4FeH to block O2 diffusion. Protein film electrochemistry experiments demonstrate increased O2 stabilities for variants G302S and S357T, and MD simulations based on high-resolution crystal structures confirmed an enhanced local sieving effect for O2 in the environment of the 4FeH in both cases. The results strongly suggest that, in wild type proteins, O2 diffuses from the 4FeH to the 2FeH . These results reveal new strategies for improving the O2 stability of [FeFe]-hydrogenases by focusing on the O2 diffusion network near the active site.
Collapse
Affiliation(s)
- Claudia Brocks
- Faculty of Biology and Biotechnology, Photobiotechnology, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Chandan K Das
- Faculty of Chemistry and Biochemistry, Center for Theoretical Chemistry, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Jifu Duan
- Faculty of Biology and Biotechnology, Photobiotechnology, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Shanika Yadav
- Faculty of Chemistry and Biochemistry, Inorganic Chemistry, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Ulf-Peter Apfel
- Faculty of Chemistry and Biochemistry, Inorganic Chemistry, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Subhasri Ghosh
- Faculty of Biology and Biotechnology, Photobiotechnology, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Eckhard Hofmann
- Faculty of Biology and Biotechnology, X-ray structure analysis of proteins, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Martin Winkler
- Electrobiotechnology, TUM Campus Straubing, Schulgasse 22, Straubing, 94315, Germany
| | - Vera Engelbrecht
- Faculty of Biology and Biotechnology, Photobiotechnology, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Lars V Schäfer
- Faculty of Chemistry and Biochemistry, Center for Theoretical Chemistry, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| | - Thomas Happe
- Faculty of Biology and Biotechnology, Photobiotechnology, Ruhr University Bochum, Universitätsstrasse 150, 44801, Bochum, Germany
| |
Collapse
|