Interaction of human CBG with cell membranes

摘要: Specific binding sites for corticosteroid-binding globulin (CBG) and its pregnancy-associated variant (pCBG), having a modified carbohydrate moiety, were found in the plasma membranes of human liver, decidual endometrium placental syncytiotrophoblast. The membrane was influenced by conformation glycoprotein molecules structure their chains. CBG receptor solubilized from partially characterized. It to have subunit structure, with homooligomeric sialoglycoprotein consisting four 20 kDa protomeric species being involved recognition complexed progesterone or cortisol. A kinetic study using microvesicles derived syncytiotrophoblast brush border revealed that neither nor pCBG restricted cortisol accumulation intravesicular space, whereas only normal could penetrate membrane. Action CBG-cortisol complex on trophoblast cells resulted activation adenylate cyclase growth cAMP within these cells. Collectively, findings suggest both are guided transport steroid hormones target transmembrane transfer and/or hormonal signals.