Linked Life Data

2914890

Source:http://linkedlifedata.com/resource/pubmed/id/2914890

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1989-3-13
pubmed:abstractText
Mechanism-based destruction of cytochrome P-450 (P-450) and P-450 heme is observed during the oxidation of N-cyclopropyl and N-cyclobutyl benzylamines. The slower inactivation by the cyclobutylamines relative to cyclopropylamines is consistent with known relative rates of ring opening of cycloalkyl-substituted aminium radicals. Evidence was found that porphyrin meso adducts of the type reported for horseradish peroxidase and cyclopropanone hydrate (Wiseman, J. S., Nichols, J. S., and Kolpak, M. X. (1982) J. Biol. Chem. 257, 6328-6332) were not formed. Radiolabels from cyclopropylamine substrates were covalently attached to protein but essentially only from the cyclopropyl portion and not the benzylic portion. Neither label appeared to be bound to extractable heme; however, during oxidations with cyclopropylamines, labeled P-450 heme became covalently attached to protein. Oxidation of 1-phenylcyclobutylamine by P-450 yielded 2-phenyl-1-pyrroline and 2-phenylpyrrolidine, and the ring expansion is interpreted as evidence for the existence of aminium radicals based on precedents with monoamine oxidase (Silverman, R. B., and Zieske, P. A. (1985) Biochemistry 24, 2128-2138). In addition, purified P-450PB-B oxidized N-(1-phenylcyclobutyl)-benzylamine to N-(1-phenyl)cyclobutyl phenyl nitrone, identified using spectral techniques. This transformation involves two sequential oxidations with either a hydroxylamine or benzylidene intermediate. While P-450 oxidized the amine to both compounds, only the hydroxylamine was rapidly oxidized to give the nitrone. The ring expansion and nitrone products are interpreted in the context of aminium radical intermediates involved in the mechanism of P-450-catalyzed amine oxidation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
264
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1988-97
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Oxidation of cycloalkylamines by cytochrome P-450. Mechanism-based inactivation, adduct formation, ring expansion, and nitrone formation.
pubmed:affiliation
Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't