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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
43
|
| pubmed:dateCreated |
1992-12-7
|
| pubmed:abstractText |
2-Ethynylnaphthalene (2EN) had previously been demonstrated to be a mechanism-based inactivator of rat cytochrome P450 (P450) 1A2 [Hammons, G.J., Alworth, W.L., Hopkins, N.E., Guengerich, F. P., & Kadlubar, F. F. (1989) Chem. Res. Toxicol. 2, 367-374]. In this work 2EN was also demonstrated to be a useful inactivator of rabbit P450 1A2 (k(inactivation) 0.094 min-1, K(i) 11 microM) but it did not inactivate human P450 1A2, although the sequences of the three proteins are approximately 80% identical. Rat and rabbit P450 1A2 were modified by incubation with NADPH-P450 reductase, NADPH, and [3H]2EN to levels of 0.35 and 0.47 nmol of adduct (nmol of P450)-1, respectively. In each case only a single tryptic peptide was labeled; recovery of labeled peptides was low under the acidic HPLC conditions. The rabbit P450 1A2 peptide FQELMAAVGR (positions 175-184) and the rat P450 1A2 peptide L(S)QQYGDVLQIR (positions 67-78) were identified. 4-Azidobiphenyl (4-N3BP) was developed as a photoaffinity label for P-450 1A2 proteins because of its similarity to 4-aminobiphenyl, a known substrate for the enzymes. 4-N3BP was shown to be photolyzed with 350-nm light and radioactive label could be incorporated into rat P450 1A2. Labeling of the protein was found to be saturable with increasing concentrations of 4-N3BP and up to 0.59 nmol of label could be incorporated (nmol P450 1A2)-1. The substrate 4-aminobiphenyl and the competitive inhibitor 7,8-benzoflavone blocked photolabeling of P450 1A2 with 4-N3BP, and 4-N3BP inhibited N-hydroxylation of 4-aminobiphenyl by P450 1A2 in the usual enzyme assay.(ABSTRACT TRUNCATED AT 250 WORDS)
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| pubmed:grant | |
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/2-ethynylnaphthalene,
http://linkedlifedata.com/resource/pubmed/chemical/Affinity Labels,
http://linkedlifedata.com/resource/pubmed/chemical/Azides,
http://linkedlifedata.com/resource/pubmed/chemical/Biphenyl Compounds,
http://linkedlifedata.com/resource/pubmed/chemical/Cytochrome P-450 CYP1A2,
http://linkedlifedata.com/resource/pubmed/chemical/Cytochrome P-450 Enzyme System,
http://linkedlifedata.com/resource/pubmed/chemical/Naphthalenes,
http://linkedlifedata.com/resource/pubmed/chemical/Oxidoreductases
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Nov
|
| pubmed:issn |
0006-2960
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
3
|
| pubmed:volume |
31
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
10556-63
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| pubmed:dateRevised |
2007-11-14
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| pubmed:meshHeading |
pubmed-meshheading:1420171-Affinity Labels,
pubmed-meshheading:1420171-Amino Acid Sequence,
pubmed-meshheading:1420171-Animals,
pubmed-meshheading:1420171-Azides,
pubmed-meshheading:1420171-Biphenyl Compounds,
pubmed-meshheading:1420171-Chromatography, High Pressure Liquid,
pubmed-meshheading:1420171-Cytochrome P-450 CYP1A2,
pubmed-meshheading:1420171-Cytochrome P-450 Enzyme System,
pubmed-meshheading:1420171-Humans,
pubmed-meshheading:1420171-Microsomes, Liver,
pubmed-meshheading:1420171-Molecular Sequence Data,
pubmed-meshheading:1420171-Naphthalenes,
pubmed-meshheading:1420171-Oxidoreductases,
pubmed-meshheading:1420171-Peptide Mapping,
pubmed-meshheading:1420171-Photochemistry,
pubmed-meshheading:1420171-Rabbits,
pubmed-meshheading:1420171-Rats,
pubmed-meshheading:1420171-Sequence Alignment
|
| pubmed:year |
1992
|
| pubmed:articleTitle |
Modification of cytochrome P450 1A2 enzymes by the mechanism-based inactivator 2-ethynylnaphthalene and the photoaffinity label 4-azidobiphenyl.
|
| pubmed:affiliation |
Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232.
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| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
|