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Hole Hopping through Tryptophan in Cytochrome P450

Ener, Maraia E. and Gray, Harry B. and Winkler, Jay R. (2017) Hole Hopping through Tryptophan in Cytochrome P450. Biochemistry, 56 (28). pp. 3531-3538. ISSN 0006-2960. PMCID PMC5518273. https://resolver.caltech.edu/CaltechAUTHORS:20170710-110217062

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Abstract

Electron-transfer kinetics have been measured in four conjugates of cytochrome P450 with surface-bound Ru-photosensitizers. The conjugates are constructed with enzymes from Bacillus megaterium (CYP102A1) and Sulfolobus acidocaldarius (CYP119). A W96 residue lies in the path between Ru and the heme in CYP102A1, whereas H76 is present at the analogous location in CYP119. Two additional conjugates have been prepared with (CYP102A1)W96H and (CYP119)H76W mutant enzymes. Heme oxidation by photochemically generated Ru^(3+) leads to P450 compound II formation when a tryptophan residue is in the path between Ru and the heme; no heme oxidation is observed when histidine occupies this position. The data indicate that heme oxidation proceeds via two-step tunneling through a tryptophan radical intermediate. In contrast, heme reduction by photochemically generated Ru+ proceeds in a single electron tunneling step with closely similar rate constants for all four conjugates.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1021/acs.biochem.7b00432DOIArticle
http://pubs.acs.org/doi/abs/10.1021/acs.biochem.7b00432PublisherArticle
http://pubs.acs.org/doi/suppl/10.1021/acs.biochem.7b00432PublisherSupporting Information
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5518273/PubMed CentralArticle
ORCID:
AuthorORCID
Gray, Harry B.0000-0002-7937-7876
Winkler, Jay R.0000-0002-4453-9716
Additional Information:© 2017 American Chemical Society. This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposes. Received: May 5, 2017; Revised: June 16, 2017; Published: July 9, 2017. Research reported in this publication was supported by the National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health under Award Number R01DK019038. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. Additional support was provided by the Arnold and Mabel Beckman Foundation. The authors declare no competing financial interest.
Funders:
Funding AgencyGrant Number
NIHR01DK019038
Arnold and Mabel Beckman FoundationUNSPECIFIED
Issue or Number:28
PubMed Central ID:PMC5518273
Record Number:CaltechAUTHORS:20170710-110217062
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20170710-110217062
Official Citation:Hole Hopping through Tryptophan in Cytochrome P450 Maraia E. Ener, Harry B. Gray, and Jay R. Winkler Biochemistry 2017 56 (28), 3531-3538 DOI: 10.1021/acs.biochem.7b00432
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:78892
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:10 Jul 2017 19:47
Last Modified:22 Nov 2019 09:58

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