Molecular modelling of CYP1A subfamily members based on an alignment with CYP102: rationalization of CYP1A substrate specificity in terms of active site amino acid residues.
1. Using a novel amino acid sequence alignment, proteins of the CYP1A subfamily have been produced from the CYP102 crystal structure template via residue replacement and energy minimization procedures. 2. Known substrates and inhibitors of CYP1A1 and CYP1A2 are shown to fit their respective active sites via key interactions with complementary amino acid residues. Substrates used in the modelling studies include: caffeine, PhIP, oestradiol, 2,4- and 2,5-diaminotoluenes, Glu-P-1, phenacetin, acetanilide, 7-methoxy and 7-ethoxyresorufins, 11-methyl cyclopenta[a]phenanthren-17-one, 7-ethoxycoumarin, aflatoxin B1, benzo[a]pyrene, benzo[a]pyrene-7,8-diol and 1'-hydroxy 3-methylcholanthrene. 3. A number of aspects relating to CYP1A substrate specificity and metabolism can be explained in terms of the enzyme models, as it is found that key interactions with active site amino acid residues direct CYP1A-mediated metabolism in the known positions.
Lewis
D F
DF
School of Biological Sciences, University of Surrey, Guildford, UK.
Lake
B G
BG
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D019475:Camphor 5-Monooxygenase / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism; D019363:Cytochrome P-450 CYP1A1 / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism; D019388:Cytochrome P-450 CYP1A2 / Q000737:chemistry* / Q000378:metabolism; D065609:Cytochrome P-450 CYP1A2 Inhibitors; D004791:Enzyme Inhibitors / Q000378:metabolism; D006801:Humans; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D011817:Rabbits; D051381:Rats; D016415:Sequence Alignment; D013379:Substrate Specificity; D014337:Trout
D065609:Cytochrome P-450 CYP1A2 Inhibitors; D004791:Enzyme Inhibitors; D019363:Cytochrome P-450 CYP1A1; D019388:Cytochrome P-450 CYP1A2; D019475:Camphor 5-Monooxygenase