Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
13
pubmed:dateCreated
1981-8-27
pubmed:abstractText
Administration of 3,5-dicarbethoxy-1,4-dihydrocollidine (DDC) to rats causes the accumulation of N-methylprotoporphyrin IX, a potent inhibitor of ferrochelatase. To clarify the origin of the porphyrin N-methyl group, we have synthesized and administered to rats N-ethyl-3,5-dicarbethoxy-1,4-dihydrocollidine (N-ethyl DDC) and 3,5-dicarbethoxy-2,6-dimethyl-4-ethyl-1,4-dihydropyridine (DDEP), the DDC analogue with a 4-ethyl rather than 4-methyl group. Only N-methylprotoporphyrin IX is isolated from rats treated with the former agent, and only N-ethylprotoporphyrin IX from those treated with the latter. All four isomers of N-ethylprotoporphyrin IX are formed biologically. The structure of the isolated porphyrins has been confirmed by complete spectroscopic comparison with the four synthetic isomers of N-ethylprotoporphyrin IX. DDEP has been shown to cause NADPH- and time-dependent in vitro loss of hepatic microsomal cytochrome P-450. These results unequivocally establish that the 4-alkyl groups in DDC and dDEP are the source of the N-alkyl group in N-methyl- and N-ethylprotoporphyrin IX, respectively, and strongly suggest that the alkyl group is transferred to the prosthetic heme of cytochrome P-450 during catalytic processing of the substrate by the enzyme. The mechanism of the group transfer is discussed.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
256
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6708-13
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
N-Alkylprotoporphyrin IX formation in 3,5-dicarbethoxy-1,4-dihydrocollidine-treated rats. Transfer of the alkyl group from the substrate to the porphyrin.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't