title: Binding of human sex hormone-binding globulin-androgen complexes to the placental syncytiotrophoblast membrane.
abstract: We have found that human SHBG complexed with androgens binds specifically to the plasma membrane of human placental syncytiotrophoblast. Apparent equilibrium association constants were 5.3.10(11) M-1 for SHBG-testosterone complex and 1.1.10(11) M-1 for SHBG-5 alpha-dihydrotestosterone. Devoid of steroid, SHBG did not bind to the membrane. This suggests that the specific membrane binding of SHBG-androgen complexes is a step of the mechanism of androgen action on syncytiotrophoblast.
authors.affiliation: Institute of Bioorganic Chemistry, Byelorussian Academy of Sciences, Minsk, U.S.S.R.
authors.forename: N I
authors.initials: NI
authors.lastname: Krupenko
authors.forename: G V
authors.initials: GV
authors.lastname: Avvakumov
authors.forename: O A
authors.initials: OA
authors.lastname: Strel'chyonok
mesh_terms: D002462:Cell Membrane / Q000378:metabolism; D005260:Female; D006801:Humans; D007700:Kinetics; D008871:Microvilli / Q000378:metabolism*; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D011485:Protein Binding; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism*; D013739:Testosterone / Q000378:metabolism*; D014327:Trophoblasts / Q000378:metabolism*
chemical_list: D012738:Sex Hormone-Binding Globulin; D013739:Testosterone