HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Eble, K. S. Articles by Dawson, J. H. Search for Related Content PubMed PubMed Citation Articles by Eble, K. S. Articles by Dawson, J. H. Social Bookmarking                      What's this?

J. Biol. Chem., Vol. 259, Issue 23, 14389-14393, 12, 1984

Novel reactivity of cytochrome P-450-CAM. Methyl hydroxylation of 5,5- difluorocamphor

KS Eble and JH Dawson

The interaction of the camphor hydroxylating P-450 isolated from Pseudomonas putida grown on camphor (P-450-CAM) with 5,5- difluorocamphor, a substrate analog in which the two methylene hydrogens at the normal site of hydroxylation have been replaced with fluorine, has been examined. This compound binds tightly to the enzyme with a dissociation constant and UV-visible absorption spectrum identical to that observed with d-camphor. In the presence of the reconstituted P-450-CAM system, 5,5-difluorocamphor is metabolized at a rate approximately one-third the rate of the physiological substrate, d- camphor, resulting in the formation of a hydroxylated product with a molecular weight of 204 as well as a minor (less than 3%) hydroxylated product of molecular weight 184. Isotopically labeled molecular oxygen (18O2) is incorporated into the major product while labeled oxygen from water (H218O) is not incorporated, clearly indicating that the hydroxyl oxygen originates from dioxygen. Proton NMR characterization (400 MHz) of the major product has led to its assignment as 5,5-difluoro-9- hydroxy-camphor, with supporting structural evidence provided by the mass spectral fragmentation pattern. The formation of 9-hydroxylated product represents the first example of methyl hydroxylation catalyzed by cytochrome P-450-CAM, indicates a change in regio-selectivity when the normal site of reaction is blocked, and supports the hypothesis that the delivery of the oxygen atom occurs from the exo side of the camphor molecule.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				M. C. Glascock, D. P. Ballou, and J. H. Dawson Direct Observation of a Novel Perturbed Oxyferrous Catalytic Intermediate during Reduced Putidaredoxin-initiated Turnover of Cytochrome P-450-CAM: PROBING THE EFFECTOR ROLE OF PUTIDAREDOXIN IN CATALYSIS J. Biol. Chem., December 23, 2005; 280(51): 42134 - 42141. [Abstract] [Full Text] [PDF]

				S. Kadkhodayan, E. D. Coulter, D. M. Maryniak, T. A. Bryson, and J. H. Dawson Uncoupling Oxygen Transfer and Electron Transfer in the Oxygenation of Camphor Analogues by Cytochrome P450-CAM J. Biol. Chem., November 24, 1995; 270(47): 28042 - 28048. [Abstract] [Full Text] [PDF]