A distal histidine mutant (H52Q) of yeast cytochrome c peroxidase catalyzes the oxidation of H(2)O(2) instead of its reduction.
A H52Q variant of yeast cytochrome c peroxidase (CcP), in which the distal histidine is replaced by glutamine, catalyzes oxidation of H(2)O(2) instead of reduction. This redirection of catalytic action is detected by protein film voltammetry. In the presence of H(2)O(2), wild-type CcP, adsorbed on a...
| Main Authors: | , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
2001
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| _version_ | 1797073400130174976 |
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| author | Bateman, L Léger, C Goodin, D Armstrong, F |
| author_facet | Bateman, L Léger, C Goodin, D Armstrong, F |
| author_sort | Bateman, L |
| collection | OXFORD |
| description | A H52Q variant of yeast cytochrome c peroxidase (CcP), in which the distal histidine is replaced by glutamine, catalyzes oxidation of H(2)O(2) instead of reduction. This redirection of catalytic action is detected by protein film voltammetry. In the presence of H(2)O(2), wild-type CcP, adsorbed on a graphite electrode, shows a strong catalytic reduction wave commencing at about 0.8V (pH 5.4); by contrast, H52Q does not exhibit this activity but instead shows a catalytic oxidation current at potentials in the region of 0.9 V. The oxidation current is partly suppressed in the presence of tetranitromethane (a superoxide scavenger) and is not observed for other mutants studied, including H52A. The only significant structural change in the H52Q variant is that the Q-52 side chain occupies the space vacated by the H-52 imidazole; specifically, the N-epsilon atom that is believed to transfer a proton and induce O--O cleavage is replaced, to within 0.75 A, by the carbamide-O. Thus, while the weakly basic amide functionality is unable to serve in the reorganization of bound H(2)O(2), it is able to facilitate its oxidation, most obviously by serving as a H-bond acceptor to assist formation of a labile superoxide intermediate. |
| first_indexed | 2024-03-06T23:21:34Z |
| format | Journal article |
| id | oxford-uuid:68e650fe-f44e-480d-8dbc-184891df81a6 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T23:21:34Z |
| publishDate | 2001 |
| record_format | dspace |
| spelling | oxford-uuid:68e650fe-f44e-480d-8dbc-184891df81a62022-03-26T18:47:59ZA distal histidine mutant (H52Q) of yeast cytochrome c peroxidase catalyzes the oxidation of H(2)O(2) instead of its reduction.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:68e650fe-f44e-480d-8dbc-184891df81a6EnglishSymplectic Elements at Oxford2001Bateman, LLéger, CGoodin, DArmstrong, FA H52Q variant of yeast cytochrome c peroxidase (CcP), in which the distal histidine is replaced by glutamine, catalyzes oxidation of H(2)O(2) instead of reduction. This redirection of catalytic action is detected by protein film voltammetry. In the presence of H(2)O(2), wild-type CcP, adsorbed on a graphite electrode, shows a strong catalytic reduction wave commencing at about 0.8V (pH 5.4); by contrast, H52Q does not exhibit this activity but instead shows a catalytic oxidation current at potentials in the region of 0.9 V. The oxidation current is partly suppressed in the presence of tetranitromethane (a superoxide scavenger) and is not observed for other mutants studied, including H52A. The only significant structural change in the H52Q variant is that the Q-52 side chain occupies the space vacated by the H-52 imidazole; specifically, the N-epsilon atom that is believed to transfer a proton and induce O--O cleavage is replaced, to within 0.75 A, by the carbamide-O. Thus, while the weakly basic amide functionality is unable to serve in the reorganization of bound H(2)O(2), it is able to facilitate its oxidation, most obviously by serving as a H-bond acceptor to assist formation of a labile superoxide intermediate. |
| spellingShingle | Bateman, L Léger, C Goodin, D Armstrong, F A distal histidine mutant (H52Q) of yeast cytochrome c peroxidase catalyzes the oxidation of H(2)O(2) instead of its reduction. |
| title | A distal histidine mutant (H52Q) of yeast cytochrome c peroxidase catalyzes the oxidation of H(2)O(2) instead of its reduction. |
| title_full | A distal histidine mutant (H52Q) of yeast cytochrome c peroxidase catalyzes the oxidation of H(2)O(2) instead of its reduction. |
| title_fullStr | A distal histidine mutant (H52Q) of yeast cytochrome c peroxidase catalyzes the oxidation of H(2)O(2) instead of its reduction. |
| title_full_unstemmed | A distal histidine mutant (H52Q) of yeast cytochrome c peroxidase catalyzes the oxidation of H(2)O(2) instead of its reduction. |
| title_short | A distal histidine mutant (H52Q) of yeast cytochrome c peroxidase catalyzes the oxidation of H(2)O(2) instead of its reduction. |
| title_sort | distal histidine mutant h52q of yeast cytochrome c peroxidase catalyzes the oxidation of h 2 o 2 instead of its reduction |
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