JBC

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Originally published In Press as doi:10.1074/jbc.M112155200 on January 30, 2002

J. Biol. Chem., Vol. 277, Issue 15, 12755-12761, April 12, 2002
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
277/15/12755    most recent
M112155200v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by LeBrun, L. A.
Right arrow Articles by Ortiz de Montellano, P. R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by LeBrun, L. A.
Right arrow Articles by Ortiz de Montellano, P. R.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?

Autocatalytic Mechanism and Consequences of Covalent Heme Attachment in the Cytochrome P4504A Family*

Laurie A. LeBrun, Ute Hoch, and Paul R. Ortiz de MontellanoDagger

From the Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143-0446

The prosthetic heme group in the CYP4A family of cytochrome P450 enzymes is covalently attached to an I-helix glutamic acid residue. This glutamic acid is conserved in the CYP4 family but is absent in other P450 families. As shown here, the glutamic acid is linked, presumably via an ester bond, to a hydroxyl group on the heme 5-methyl group. Mutation of the glutamic acid to an alanine in CYP4A1, CYP4A3, and CYP4A11 suppresses covalent heme binding. In wild-type CYP4A3 68% of the heme is covalently bound to the heterologously expressed protein, but in the CYP4A3/E318D mutant, 47% of the heme is unchanged, 47% is present as noncovalently bound 5-hydroxymethylheme, and only 6% is covalently bound to the protein. In the CYP4A3/E318Q mutant, the majority of the heme is unaltered, and <2% is covalently linked. The proportion of covalently bound heme in the recombinant CYP4A proteins increases with time under turnover conditions. The catalytic activity is sensitive in some, but not all, CYP4A enzymes to the extent of covalent heme binding. Mutations of Glu318 in CYP4A3 decrease the apparent kcat values for lauric acid hydroxylation. The key conclusions are that (a) covalent heme binding occurs via an ester bond to the heme 5-methyl group, (b) covalent binding of the heme is mediated by an autocatalytic process, and (c) fatty acid oxidation is sensitive in some CYP4A enzymes to the presence or absence of the heme covalent link.

* This work was supported by National Institutes of Health Grant GM25515.The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

Dagger To whom correspondence should be addressed: Dept. of Pharmaceutical Chemistry, University of California, San Francisco, School of Pharmacy, S-926, 513 Parnassus Ave., San Francisco, CA 94143-0446. Fax: 415-502-4728; E-mail: ortiz@cgl.ucsf.edu.

Copyright © 2002 by The American Society for Biochemistry and Molecular Biology, Inc.
Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?


This article has been cited by other articles:


Home page
 J. Lipid Res.Home page
M. Fer, L. Corcos, Y. Dreano, E. Plee-Gautier, J.-P. Salaun, F. Berthou, and Y. Amet
Cytochromes P450 from family 4 are the main omega hydroxylating enzymes in humans: CYP4F3B is the prominent player in PUFA metabolism
J. Lipid Res., November 1, 2008; 49(11): 2379 - 2389.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
C. Colas and P. R. O. de Montellano
Horseradish Peroxidase Mutants That Autocatalytically Modify Their Prosthetic Heme Group: INSIGHTS INTO MAMMALIAN PEROXIDASE HEME-PROTEIN COVALENT BONDS
J. Biol. Chem., June 4, 2004; 279(23): 24131 - 24140.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
H. M. Girvan, K. R. Marshall, R. J. Lawson, D. Leys, M. G. Joyce, J. Clarkson, W. E. Smith, M. R. Cheesman, and A. W. Munro
Flavocytochrome P450 BM3 Mutant A264E Undergoes Substrate-dependent Formation of a Novel Heme Iron Ligand Set
J. Biol. Chem., May 28, 2004; 279(22): 23274 - 23286.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
O. M. Lardinois and P. R. O. de Montellano
Intra- and Intermolecular Transfers of Protein Radicals in the Reactions of Sperm Whale Myoglobin with Hydrogen Peroxide
J. Biol. Chem., September 19, 2003; 278(38): 36214 - 36226.
[Abstract] [Full Text] [PDF]

Home page
 Mol. Pharmacol.Home page
B. A. Carr, S. Ramakanth, G. A. Dannan, and G. S. Yost
Characterization of Pulmonary CYP4B2, Specific Catalyst of Methyl Oxidation of 3-Methylindole
Mol. Pharmacol., May 1, 2003; 63(5): 1137 - 1147.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
 All ASBMB Journals   Molecular and Cellular Proteomics 
 Journal of Lipid Research   ASBMB Today 
Copyright © 2002 by the American Society for Biochemistry and Molecular Biology.