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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
1
|
| pubmed:dateCreated |
1996-8-15
|
| pubmed:abstractText |
Cytochrome P450 2D6 (CYP2D6) catalyzes the oxidation of substrates with a positively charged nitrogen atom 5-7 angstroms from the site of the oxidation. The active-site topology of CYP2D6 is examined here with phenyl-, 2-naphthyl-, and p-biphenyldiazene, which react with P450 enzymes to form sigma-bonded aryl-iron (Fe-Ar) complexes. Ferricyanide-mediated migration of the aryl group from the iron to the porphyrin nitrogens produces the N-arylprotoporphyrin IX regioisomers (NB:NA:NC:ND, in which the aryl group is bound to the nitrogen of pyrrole rings B, A, C, and D, respectively) in the following ratios (zero means <5%): phenyl, 10:90:00:00; 2-naphthyl, 09:91:00:00; and p-biphenyl, 16:84:00:00. These results suggest that the CYP2D6 active site is open above pyrrole ring A and to a small extent above pyrrole ring B but is closed above pyrrole rings C and D. This geometry differs from those determined by the same method for P450s for which crystal structures are available. Replacement of Asp-301 by a Glu, which preserves the carboxylate side chain, causes no detectable change in the N-aryl porphyrin regioisomer patterns and only minor changes in the catalytic activity. Replacement of Asp-301 by an Asn or Gly, which eliminates the negatively charged side chain, suppresses migration of the aryl groups to pyrrole ring B without impairing migration to pyrrole ring A and virtually abolishes catalytic activity. These results provide a refined model of the active site of CYP2D6. They confirm, furthermore, that the loss of activity observed when Asp-301 is replaced by a neutral residue is due to loss of the charge-pairing interaction with the substrate positive charge and/or subtle structural effects in the vicinity of pyrrole ring B, but not to major structural reorganization of the active site.
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| pubmed:grant | |
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Asparagine,
http://linkedlifedata.com/resource/pubmed/chemical/Aspartic Acid,
http://linkedlifedata.com/resource/pubmed/chemical/Cytochrome P-450 CYP2D6,
http://linkedlifedata.com/resource/pubmed/chemical/Cytochrome P-450 Enzyme System,
http://linkedlifedata.com/resource/pubmed/chemical/Glutamic Acid,
http://linkedlifedata.com/resource/pubmed/chemical/Glycine,
http://linkedlifedata.com/resource/pubmed/chemical/Hydrazines,
http://linkedlifedata.com/resource/pubmed/chemical/Imines,
http://linkedlifedata.com/resource/pubmed/chemical/Mixed Function Oxygenases,
http://linkedlifedata.com/resource/pubmed/chemical/Protoporphyrins,
http://linkedlifedata.com/resource/pubmed/chemical/phenyldiazene,
http://linkedlifedata.com/resource/pubmed/chemical/protoporphyrin IX
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Jul
|
| pubmed:issn |
0003-9861
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
1
|
| pubmed:volume |
331
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
134-40
|
| pubmed:dateRevised |
2007-11-14
|
| pubmed:meshHeading |
pubmed-meshheading:8660692-Asparagine,
pubmed-meshheading:8660692-Aspartic Acid,
pubmed-meshheading:8660692-Binding Sites,
pubmed-meshheading:8660692-Cytochrome P-450 CYP2D6,
pubmed-meshheading:8660692-Cytochrome P-450 Enzyme System,
pubmed-meshheading:8660692-Electrochemistry,
pubmed-meshheading:8660692-Glutamic Acid,
pubmed-meshheading:8660692-Glycine,
pubmed-meshheading:8660692-Humans,
pubmed-meshheading:8660692-Hydrazines,
pubmed-meshheading:8660692-Imines,
pubmed-meshheading:8660692-Mixed Function Oxygenases,
pubmed-meshheading:8660692-Models, Molecular,
pubmed-meshheading:8660692-Molecular Structure,
pubmed-meshheading:8660692-Mutation,
pubmed-meshheading:8660692-Protoporphyrins,
pubmed-meshheading:8660692-Saccharomyces cerevisiae,
pubmed-meshheading:8660692-Structure-Activity Relationship
|
| pubmed:year |
1996
|
| pubmed:articleTitle |
Active-site topologies of human CYP2D6 and its aspartate-301 --> glutamate, asparagine, and glycine mutants.
|
| pubmed:affiliation |
Department of Pharmaceutical Chemistry, University of California, San Francisco 94143-0446, USA.
|
| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
|