The structure of plastocyanin tunes the midpoint potential by restricting axial ligation of the reduced copper ion
Abstract Blue copper proteins are models for illustrating how proteins tune metal properties. Nevertheless, the mechanisms by which the protein controls the metal site remain to be fully elucidated. A hindrance is that the closed shell Cu(I) site is inaccessible to most spectroscopic analyses. Carbo...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2023-08-01
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| Series: | Communications Chemistry |
| Online Access: | https://doi.org/10.1038/s42004-023-00977-4 |
| _version_ | 1797577633850982400 |
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| author | Claire C. Mammoser Brynn E. LeMasters Sydney G. Edwards Emma M. McRae M. Hunter Mullins Yiqi Wang Nicholas M. Garcia Katherine A. Edmonds David P. Giedroc Megan C. Thielges |
| author_facet | Claire C. Mammoser Brynn E. LeMasters Sydney G. Edwards Emma M. McRae M. Hunter Mullins Yiqi Wang Nicholas M. Garcia Katherine A. Edmonds David P. Giedroc Megan C. Thielges |
| author_sort | Claire C. Mammoser |
| collection | DOAJ |
| description | Abstract Blue copper proteins are models for illustrating how proteins tune metal properties. Nevertheless, the mechanisms by which the protein controls the metal site remain to be fully elucidated. A hindrance is that the closed shell Cu(I) site is inaccessible to most spectroscopic analyses. Carbon deuterium (C-D) bonds used as vibrational probes afford nonperturbative, selective characterization of the key cysteine and methionine copper ligands in both redox states. The structural integrity of Nostoc plastocyanin was perturbed by disrupting potential hydrogen bonds between loops of the cupredoxin fold via mutagenesis (S9A, N33A, N34A), variably raising the midpoint potential. The C-D vibrations show little change to suggest substantial alteration to the Cu(II) coordination in the oxidized state or in the Cu(I) interaction with the cysteine ligand. They rather indicate, along with visible and NMR spectroscopy, that the methionine ligand distinctly interacts more strongly with the Cu(I) ion, in line with the increases in midpoint potential. Here we show that the protein structure determines the redox properties by restricting the interaction between the methionine ligand and Cu(I) in the reduced state. |
| first_indexed | 2024-03-10T22:10:51Z |
| format | Article |
| id | doaj.art-f73a1aa8abd44131a24ab020e3fde38c |
| institution | Directory Open Access Journal |
| issn | 2399-3669 |
| language | English |
| last_indexed | 2024-03-10T22:10:51Z |
| publishDate | 2023-08-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Communications Chemistry |
| spelling | doaj.art-f73a1aa8abd44131a24ab020e3fde38c2023-11-19T12:37:30ZengNature PortfolioCommunications Chemistry2399-36692023-08-01611910.1038/s42004-023-00977-4The structure of plastocyanin tunes the midpoint potential by restricting axial ligation of the reduced copper ionClaire C. Mammoser0Brynn E. LeMasters1Sydney G. Edwards2Emma M. McRae3M. Hunter Mullins4Yiqi Wang5Nicholas M. Garcia6Katherine A. Edmonds7David P. Giedroc8Megan C. Thielges9Indiana University Department of ChemistryIndiana University Department of ChemistryIndiana University Department of ChemistryIndiana University Department of ChemistryIndiana University Department of ChemistryIndiana University Department of ChemistryIndiana University Department of ChemistryIndiana University Department of ChemistryIndiana University Department of ChemistryIndiana University Department of ChemistryAbstract Blue copper proteins are models for illustrating how proteins tune metal properties. Nevertheless, the mechanisms by which the protein controls the metal site remain to be fully elucidated. A hindrance is that the closed shell Cu(I) site is inaccessible to most spectroscopic analyses. Carbon deuterium (C-D) bonds used as vibrational probes afford nonperturbative, selective characterization of the key cysteine and methionine copper ligands in both redox states. The structural integrity of Nostoc plastocyanin was perturbed by disrupting potential hydrogen bonds between loops of the cupredoxin fold via mutagenesis (S9A, N33A, N34A), variably raising the midpoint potential. The C-D vibrations show little change to suggest substantial alteration to the Cu(II) coordination in the oxidized state or in the Cu(I) interaction with the cysteine ligand. They rather indicate, along with visible and NMR spectroscopy, that the methionine ligand distinctly interacts more strongly with the Cu(I) ion, in line with the increases in midpoint potential. Here we show that the protein structure determines the redox properties by restricting the interaction between the methionine ligand and Cu(I) in the reduced state.https://doi.org/10.1038/s42004-023-00977-4 |
| spellingShingle | Claire C. Mammoser Brynn E. LeMasters Sydney G. Edwards Emma M. McRae M. Hunter Mullins Yiqi Wang Nicholas M. Garcia Katherine A. Edmonds David P. Giedroc Megan C. Thielges The structure of plastocyanin tunes the midpoint potential by restricting axial ligation of the reduced copper ion Communications Chemistry |
| title | The structure of plastocyanin tunes the midpoint potential by restricting axial ligation of the reduced copper ion |
| title_full | The structure of plastocyanin tunes the midpoint potential by restricting axial ligation of the reduced copper ion |
| title_fullStr | The structure of plastocyanin tunes the midpoint potential by restricting axial ligation of the reduced copper ion |
| title_full_unstemmed | The structure of plastocyanin tunes the midpoint potential by restricting axial ligation of the reduced copper ion |
| title_short | The structure of plastocyanin tunes the midpoint potential by restricting axial ligation of the reduced copper ion |
| title_sort | structure of plastocyanin tunes the midpoint potential by restricting axial ligation of the reduced copper ion |
| url | https://doi.org/10.1038/s42004-023-00977-4 |
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