Binding characteristics of seven inhibitors of human aromatase: a site-directed mutagenesis study.
Aromatase, a cytochrome P450, catalyzes three consecutive hydroxylation reactions converting C19 androgens to aromatic C18 estrogenic steroids. In this study, eight human aromatase mutants (I133Y, I133W, F235L, I395F, I474Y, I474W, I474M, and I474N) were prepared to evaluate the active site and a proposed hydrophobic pocket of the enzyme that exists in an aromatase model based on the X-ray structure of cytochrome P450cam. In addition, the binding characteristics of three steroidal inhibitors [4-hydroxyandrostenedione, 7alpha-(4'-amino)phenylthio-1,4-androstandiene-3,17-dione, and bridge (2,19-methyleneoxy)androstene-3,17-dione (MDL 101,003)] and four nonsteroidal inhibitors [aminoglutethimide, CGS 20267, ICI D1033, and vorozole (R83842)] were investigated through inhibitory profile studies on the eight new and three previously generated mutants (P308F, D309A, and T310S). The latter analyses have provided a molecular basis regarding how seven aromatase inhibitors with different structures bind to the active site of aromatase.
Kao
Y C
YC
Division of Immunology, Beckman Research Institute of the City of Hope, Duarte, California 91010, USA.
Cam
L L
LL
Laughton
C A
CA
Zhou
D
D
Chen
S
S
D000595:Amino Acid Sequence; D000818:Animals; D001141:Aromatase / Q000235:genetics / Q000378:metabolism; D047072:Aromatase Inhibitors; D001426:Bacterial Proteins; D016466:CHO Cells; D019475:Camphor 5-Monooxygenase; D006224:Cricetinae; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics; D004791:Enzyme Inhibitors / Q000378:metabolism* / Q000494:pharmacology; D005260:Female; D006801:Humans; D006899:Mixed Function Oxygenases / Q000235:genetics; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009251:NADPH-Ferrihemoprotein Reductase; D011487:Protein Conformation; D011817:Rabbits; D017386:Sequence Homology, Amino Acid
D047072:Aromatase Inhibitors; D001426:Bacterial Proteins; D004791:Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; D001141:Aromatase; D019475:Camphor 5-Monooxygenase; D009251:NADPH-Ferrihemoprotein Reductase; C052423:flavocytochrome P450 BM3 monoxygenases