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Title: Highly reactive electrophilic oxidants in cytochrome P450 catalysis

Abstract

The cytochrome P450 enzymes effect a wide range of oxidations in nature including difficult hydroxylation reactions of unactivated C-H. Most of the high energy reactions of these catalysts appear to involve highly electrophilic active species. Attempts to detect the reactive transients in the enzymes have met with limited success, but evidence has accumulated that two distinct electrophilic oxidants are produced in the P450 enzymes. The consensus electrophilic oxidant termed 'iron-oxo' is usually thought to be an analogue of Compound I, an iron(IV)-oxo porphyrin radical cation species, but it is possible that a higher energy electronic isomer of Compound I is required to account for the facility of the C-H oxidation reactions. The second electrophilic oxidant of P450 is speculative; circumstantial evidence suggests that this species is iron-complexed hydrogen peroxide, but this oxidant might be a second spin state of iron-oxo. This overview discusses recent studies directed at detection of the electrophilic oxidants in P450 enzymes and the accumulated evidence for two distinct species.

Authors:
 [1];  [2]
  1. Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor St., Chicago, IL 60607 (United States). E-mail: men@uic.edu
  2. Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor St., Chicago, IL 60607 (United States)
Publication Date:
OSTI Identifier:
20793204
Resource Type:
Journal Article
Resource Relation:
Journal Name: Biochemical and Biophysical Research Communications; Journal Volume: 338; Journal Issue: 1; Other Information: DOI: 10.1016/j.bbrc.2005.08.208; PII: S0006-291X(05)01915-7; Copyright (c) 2005 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; CATALYSIS; CATALYSTS; CATIONS; ENZYMES; HYDROGEN PEROXIDE; HYDROXYLATION; IRON; ISOMERS; OXIDATION; OXIDIZERS; PORPHYRINS; SPIN

Citation Formats

Newcomb, Martin, and Chandrasena, R. Esala P. Highly reactive electrophilic oxidants in cytochrome P450 catalysis. United States: N. p., 2005. Web. doi:10.1016/J.BBRC.2005.0.
Newcomb, Martin, & Chandrasena, R. Esala P. Highly reactive electrophilic oxidants in cytochrome P450 catalysis. United States. doi:10.1016/J.BBRC.2005.0.
Newcomb, Martin, and Chandrasena, R. Esala P. Fri . "Highly reactive electrophilic oxidants in cytochrome P450 catalysis". United States. doi:10.1016/J.BBRC.2005.0.
@article{osti_20793204,
title = {Highly reactive electrophilic oxidants in cytochrome P450 catalysis},
author = {Newcomb, Martin and Chandrasena, R. Esala P.},
abstractNote = {The cytochrome P450 enzymes effect a wide range of oxidations in nature including difficult hydroxylation reactions of unactivated C-H. Most of the high energy reactions of these catalysts appear to involve highly electrophilic active species. Attempts to detect the reactive transients in the enzymes have met with limited success, but evidence has accumulated that two distinct electrophilic oxidants are produced in the P450 enzymes. The consensus electrophilic oxidant termed 'iron-oxo' is usually thought to be an analogue of Compound I, an iron(IV)-oxo porphyrin radical cation species, but it is possible that a higher energy electronic isomer of Compound I is required to account for the facility of the C-H oxidation reactions. The second electrophilic oxidant of P450 is speculative; circumstantial evidence suggests that this species is iron-complexed hydrogen peroxide, but this oxidant might be a second spin state of iron-oxo. This overview discusses recent studies directed at detection of the electrophilic oxidants in P450 enzymes and the accumulated evidence for two distinct species.},
doi = {10.1016/J.BBRC.2005.0},
journal = {Biochemical and Biophysical Research Communications},
number = 1,
volume = 338,
place = {United States},
year = {Fri Dec 09 00:00:00 EST 2005},
month = {Fri Dec 09 00:00:00 EST 2005}
}
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