EPR and ENDOR detection of compound I from Micrococcus lysodeikticus catalase.
We present the first EPR and ENDOR examination of a catalase compound I (Cat I), the one formed by peracetic acid treatment of Micrococcus lysodeikticus catalase. The Cat I rapid-passage EPR signal (g perpendicular eff = 3.32; g parallel eff approximately 2) appears quite different from those report...
| Main Authors: | , , , , |
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| Format: | Journal article |
| Language: | English |
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1993
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| _version_ | 1797091406666268672 |
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| author | Benecky, M Frew, J Scowen, N Jones, P Hoffman, B |
| author_facet | Benecky, M Frew, J Scowen, N Jones, P Hoffman, B |
| author_sort | Benecky, M |
| collection | OXFORD |
| description | We present the first EPR and ENDOR examination of a catalase compound I (Cat I), the one formed by peracetic acid treatment of Micrococcus lysodeikticus catalase. The Cat I rapid-passage EPR signal (g perpendicular eff = 3.32; g parallel eff approximately 2) appears quite different from those reported previously for the compounds I from horseradish peroxidase (HRP I) and chloroperoxidase. Nonetheless, all three signals can be explained by the same model for exchange coupling between an S = 1 oxoferryl [Fe = O]2+ moiety and a porphyrin pi-cation radical (S' = 1/2) (Schulz, C. E., et al. (1979) FEBS Lett. 103, 102-105). The signal for Cat I is unlike those for the two peroxidases in that it reflects a ferromagnetic rather than antiferromagnetic exchange. Preliminary 1H ENDOR spectra for Cat I appear to differ from the proton (1H) ENDOR spectra of HRP I; the latter, along with the 14N ENDOR spectra, indicate that the porphyrin radical in HRP I exhibits a predominantly A2u-like state having large spin densities on porphyrin N and C(beta). The proton ENDOR spectrum of Cat I is insensitive to H/D exchange, which indicates that the [Fe = O]2+ moiety is not protonated. Consideration of the EPR results for a series of compounds I suggests that the sign and magnitude of the exchange parameter (J) is correlated with the nature of the proximal axial ligand. |
| first_indexed | 2024-03-07T03:32:35Z |
| format | Journal article |
| id | oxford-uuid:bb38029d-a054-4bf2-ab7b-f095044409c2 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T03:32:35Z |
| publishDate | 1993 |
| record_format | dspace |
| spelling | oxford-uuid:bb38029d-a054-4bf2-ab7b-f095044409c22022-03-27T05:15:23ZEPR and ENDOR detection of compound I from Micrococcus lysodeikticus catalase.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:bb38029d-a054-4bf2-ab7b-f095044409c2EnglishSymplectic Elements at Oxford1993Benecky, MFrew, JScowen, NJones, PHoffman, BWe present the first EPR and ENDOR examination of a catalase compound I (Cat I), the one formed by peracetic acid treatment of Micrococcus lysodeikticus catalase. The Cat I rapid-passage EPR signal (g perpendicular eff = 3.32; g parallel eff approximately 2) appears quite different from those reported previously for the compounds I from horseradish peroxidase (HRP I) and chloroperoxidase. Nonetheless, all three signals can be explained by the same model for exchange coupling between an S = 1 oxoferryl [Fe = O]2+ moiety and a porphyrin pi-cation radical (S' = 1/2) (Schulz, C. E., et al. (1979) FEBS Lett. 103, 102-105). The signal for Cat I is unlike those for the two peroxidases in that it reflects a ferromagnetic rather than antiferromagnetic exchange. Preliminary 1H ENDOR spectra for Cat I appear to differ from the proton (1H) ENDOR spectra of HRP I; the latter, along with the 14N ENDOR spectra, indicate that the porphyrin radical in HRP I exhibits a predominantly A2u-like state having large spin densities on porphyrin N and C(beta). The proton ENDOR spectrum of Cat I is insensitive to H/D exchange, which indicates that the [Fe = O]2+ moiety is not protonated. Consideration of the EPR results for a series of compounds I suggests that the sign and magnitude of the exchange parameter (J) is correlated with the nature of the proximal axial ligand. |
| spellingShingle | Benecky, M Frew, J Scowen, N Jones, P Hoffman, B EPR and ENDOR detection of compound I from Micrococcus lysodeikticus catalase. |
| title | EPR and ENDOR detection of compound I from Micrococcus lysodeikticus catalase. |
| title_full | EPR and ENDOR detection of compound I from Micrococcus lysodeikticus catalase. |
| title_fullStr | EPR and ENDOR detection of compound I from Micrococcus lysodeikticus catalase. |
| title_full_unstemmed | EPR and ENDOR detection of compound I from Micrococcus lysodeikticus catalase. |
| title_short | EPR and ENDOR detection of compound I from Micrococcus lysodeikticus catalase. |
| title_sort | epr and endor detection of compound i from micrococcus lysodeikticus catalase |
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