title: Molecular basis for the aromatization reaction and exemestane-mediated irreversible inhibition of human aromatase.
abstract: Aromatase converts androgens to aromatic estrogens. Aromatase inhibitors have been used as first-line drugs in the treatment of hormone-dependent breast cancer. Structural basis of the aromatization reaction and drug recognition by aromatase has remained elusive because of its unknown three-dimensional structure. In this study, recombinant human aromatase was expressed and purified from Escherichia coli. Using this purified and active preparation, the three-dimensional folding of aromatase was revealed by proteomic analysis. Combined with site-directed mutagenesis, several critical residues involved in enzyme catalysis and suicide inhibition by exemestane were evaluated. Based on our results, a new clamping mechanism of substrate/exemestane binding to the active site is proposed. These structure-function studies of aromatase would provide useful information to design more effective aromatase inhibitors for the prevention and the treatment of hormone-dependent breast cancer.
authors.affiliation: Department of Surgical Research and Division of Information Sciences, Beckman Research Institute of the City of Hope, 1500 East Duarte Road, Duarte, California 91010, USA.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Hong
authors.forename: Bin
authors.initials: B
authors.lastname: Yu
authors.forename: Mark
authors.initials: M
authors.lastname: Sherman
authors.forename: Yate-Ching
authors.initials: YC
authors.lastname: Yuan
authors.forename: Dujin
authors.initials: D
authors.lastname: Zhou
authors.forename: Shiuan
authors.initials: S
authors.lastname: Chen
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000730:Androstadienes / Q000737:chemistry*; D001141:Aromatase / Q000737:chemistry* / Q000235:genetics; D047072:Aromatase Inhibitors / Q000737:chemistry*; D001665:Binding Sites; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D017510:Protein Folding; D040901:Proteomics; D011994:Recombinant Proteins / Q000737:chemistry; D013329:Structure-Activity Relationship
chemical_list: D000730:Androstadienes; D047072:Aromatase Inhibitors; D011994:Recombinant Proteins; D001141:Aromatase; C056516:exemestane