Iron-sulphur clusters with labile metal ions.
A study has been carried out of the redox-linked metal ion uptake processes of the iron-sulphur cluster [3Fe-4S] in the bacterial ferredoxin, Fd III from Desulphovibrio africanus using a combination of electron paramagnetic resonance (EPR) and low-temperature magnetic circular dichroism (MCD) spectr...
| Main Authors: | , , , , |
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| Format: | Conference item |
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1992
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| _version_ | 1797092512920240128 |
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| author | Thomson, A Breton, J Butt, J Hatchikian, E Armstrong, F |
| author_facet | Thomson, A Breton, J Butt, J Hatchikian, E Armstrong, F |
| author_sort | Thomson, A |
| collection | OXFORD |
| description | A study has been carried out of the redox-linked metal ion uptake processes of the iron-sulphur cluster [3Fe-4S] in the bacterial ferredoxin, Fd III from Desulphovibrio africanus using a combination of electron paramagnetic resonance (EPR) and low-temperature magnetic circular dichroism (MCD) spectroscopy and direct, unmediated electrochemistry of the Fd in a film deposited at a pyrolytic graphite electrode. Reduction of the three-iron cluster is required before a divalent metal ion becomes bound as in the reaction sequence [formula: see text] The redox potentials of these processes and the metal binding constants have been determined. The affinities of the [3Fe-4S]0 cluster for divalent ions lie in the sequence Cd greater than Zn much greater than Fe. In addition, specific binding of a monovalent ion, Thallium(I), is detected for [3Fe-4S]1+ as well as for [3Fe-4S]0. The results provide a clear and quantitative demonstration of the capability of the open triangular tri-mu 2-sulphido face of a [3Fe-4S] cluster to bind a variety of metal ions if the protein environment permits. In each case the entering metal ion is coordinated by at least one additional ligand which may be from solvent (H2O or OH-) or from a protein side chain (e.g., carboxylate from aspartic acid). Hence the [3Fe-4S] core can be a redox-linked sensor of divalent metal ions, Fe(II) or Zn(II), that may trigger conformational change. |
| first_indexed | 2024-03-07T03:46:59Z |
| format | Conference item |
| id | oxford-uuid:bfd33270-27fb-4735-8af5-c173d910319f |
| institution | University of Oxford |
| last_indexed | 2024-03-07T03:46:59Z |
| publishDate | 1992 |
| record_format | dspace |
| spelling | oxford-uuid:bfd33270-27fb-4735-8af5-c173d910319f2022-03-27T05:50:15ZIron-sulphur clusters with labile metal ions.Conference itemhttp://purl.org/coar/resource_type/c_5794uuid:bfd33270-27fb-4735-8af5-c173d910319fSymplectic Elements at Oxford1992Thomson, ABreton, JButt, JHatchikian, EArmstrong, FA study has been carried out of the redox-linked metal ion uptake processes of the iron-sulphur cluster [3Fe-4S] in the bacterial ferredoxin, Fd III from Desulphovibrio africanus using a combination of electron paramagnetic resonance (EPR) and low-temperature magnetic circular dichroism (MCD) spectroscopy and direct, unmediated electrochemistry of the Fd in a film deposited at a pyrolytic graphite electrode. Reduction of the three-iron cluster is required before a divalent metal ion becomes bound as in the reaction sequence [formula: see text] The redox potentials of these processes and the metal binding constants have been determined. The affinities of the [3Fe-4S]0 cluster for divalent ions lie in the sequence Cd greater than Zn much greater than Fe. In addition, specific binding of a monovalent ion, Thallium(I), is detected for [3Fe-4S]1+ as well as for [3Fe-4S]0. The results provide a clear and quantitative demonstration of the capability of the open triangular tri-mu 2-sulphido face of a [3Fe-4S] cluster to bind a variety of metal ions if the protein environment permits. In each case the entering metal ion is coordinated by at least one additional ligand which may be from solvent (H2O or OH-) or from a protein side chain (e.g., carboxylate from aspartic acid). Hence the [3Fe-4S] core can be a redox-linked sensor of divalent metal ions, Fe(II) or Zn(II), that may trigger conformational change. |
| spellingShingle | Thomson, A Breton, J Butt, J Hatchikian, E Armstrong, F Iron-sulphur clusters with labile metal ions. |
| title | Iron-sulphur clusters with labile metal ions. |
| title_full | Iron-sulphur clusters with labile metal ions. |
| title_fullStr | Iron-sulphur clusters with labile metal ions. |
| title_full_unstemmed | Iron-sulphur clusters with labile metal ions. |
| title_short | Iron-sulphur clusters with labile metal ions. |
| title_sort | iron sulphur clusters with labile metal ions |
| work_keys_str_mv | AT thomsona ironsulphurclusterswithlabilemetalions AT bretonj ironsulphurclusterswithlabilemetalions AT buttj ironsulphurclusterswithlabilemetalions AT hatchikiane ironsulphurclusterswithlabilemetalions AT armstrongf ironsulphurclusterswithlabilemetalions |