Preparation of an activity-inhibiting monoclonal antibody against human placental aromatase cytochrome P450.
We produced a murine monoclonal antibody (MAb) to human placental aromatase cytochrome P450. This MAb, designated MAb3-2C2, was selected on its ability to suppress aromatase activity. The specificity of this MAb was assessed by selective immunoprecipitation of 125I-labeled aromatase cytochrome P450 as well as by the identification of a 55-kDa protein, which was enriched and purified by immunoaffinity chromatography on a MAb-coupled Sepharose 4B column. The MAb was able to suppress both human placental and ovarian microsomal aromatase. Species differences of aromatase were recognized by MAb3-2C2 on the basis of differential immunosuppression of aromatase activity. The antibody had no effect on non-aromatase cytochrome P450s. MAb3-2C2 gave negative results with human placental aromatase P450 in the Western blot analysis. The data presented indicate that MAb3-2C2 is specific for aromatase cytochrome P450 and that its epitope is located in a fragile tertiary conformation of the enzyme, thus making it capable of sensitively affecting catalysis.
Washida
N
N
Endocrine Biochemistry Department, Hauptman-Woodward Medical Research Institute, Inc., Buffalo, NY 14203-1196, USA.
Kitawaki
J
J
Higashiyama
T
T
Matsui
S
S
Osawa
Y
Y
D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D000918:Antibody Specificity; D047072:Aromatase Inhibitors; D005260:Female; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008861:Microsomes / Q000201:enzymology; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy
D000911:Antibodies, Monoclonal; D047072:Aromatase Inhibitors