title: Competitive inhibition of [3H]dexamethasone binding to mammary glucocorticoid receptor by leupeptin.
abstract: The inhibitory effect of leupeptin on [3H]dexamethasone binding to the glucocorticoid receptor from lactating goat mammary cytosol has been studied. Leupeptin (10 mM) caused a significant (about 35%) inhibition of [3H]dexamethasone binding to glucocorticoid receptor. Binding inhibition is further increased following filtration of unlabeled cytosolic receptor through a Bio-Gel A 0.5-m column. Binding inhibition was partially reversed by monothioglycerol at 10 mM concentration. A double reciprocal plot revealed that leupeptin appears to be a competitive inhibitor of [3H]dexamethasone binding to the glucocorticoid receptor. Low salt sucrose density gradient centrifugation revealed that the leupeptin-treated sample formed a slightly larger (approximately 9 S) receptor complex (leupeptin-free complex sediments at 8 S).
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D002499:Centrifugation, Density Gradient; D003907:Dexamethasone / Q000037:antagonists & inhibitors* / Q000378:metabolism; D005260:Female; D006041:Goats; D007700:Kinetics; D007976:Leupeptins / Q000378:metabolism*; D008321:Mammary Glands, Animal / Q000378:metabolism*; D009842:Oligopeptides / Q000378:metabolism*; D011965:Receptors, Glucocorticoid / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D007976:Leupeptins; D009842:Oligopeptides; D011965:Receptors, Glucocorticoid; D003907:Dexamethasone; C032854:leupeptin