Binding of 2-hydroxybenzo(a)pyrene to estrogen receptors in rat cytosol.
The potent carcinogen 2-hydroxybenzo(a)pyrene (2-OH-BP) competes for binding to the estrogen receptor in the cytosol of rat uterus and liver. The dissociation constant (K1) for this interaction is congruent to 2 X 10(-5) M. In contrast, 4-hydroxybenzo(a)pyrene does not bind to the estrogen receptor; 1-hydroxybenzo(a)pyrene, 5-hydroxybenzo(a)pyrene, 6-hydroxybenzo(a)pyrene, and 12-hydroxybenzo(a)pyrene bind less tightly than does 2-OH-BP. These five chemicals are not carcinogenic. We suggest that the estrogen receptor may mediate the carcinogenic effect of 2-OH-BP or of related chemicals. One possibility is that the receptor might convey 2-OH-BP to specific sites in DNA.
D000818:Animals; D001580:Benzopyrenes / Q000378:metabolism*; D001667:Binding, Competitive; D003600:Cytosol / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism; D005260:Female; D051381:Rats; D011960:Receptors, Estrogen / Q000378:metabolism*; D013329:Structure-Activity Relationship; D014599:Uterus / Q000378:metabolism
D001580:Benzopyrenes; D011960:Receptors, Estrogen; D004958:Estradiol; C023394:2-hydroxybenzo(a)pyrene