[The effect of enzymes on progesterone-receptor binding and chromatin binding of the complex in the estrogen-primed rabbit uterus (author's transl)].
The present study was designed to determine the characteristics of the progesterone receptor and chromatin binding site ("acceptor") of the progesterone-receptor complex in the rabbit uterus. The uterus was obtained from an estrogen-primed immature female rabbit. The binding of progesterone to the uterine receptor was examined in vitro. The progesterone-receptor binding was reduced only by proteases, and phosphorus moiety may not be related for progesterone-receptor binding. The effects of enzymes on the acceptor of the chromatin were investigated. The progesterone-receptor complex was bound to the dehistonized chromatin. The dehistonized chromatins, which were pretreated with enzymes at 4 degrees C or 37 degrees C for 30 minutes, were incubated with 3H-progesterone prelabeled uterine cytosol at 4 degrees C for 30 minutes, and the radioactivity in the chromatin pellet was counted. Proteases effectively decreased the receptor binding capacity to the dehistonized chromatin in the following order: pronase greater than trypsin greater than papain greater alpha-chymotrypsin. DNAse moderately and phospholipase A slightly decreased its binding capacity. The results may indicate that the acceptor site of the progesterone receptor is nonhistone protein over DNA of chromatin and may contain phosphorus moiety.
D000818:Animals; D001665:Binding Sites; D002843:Chromatin / Q000378:metabolism*; D003851:Deoxyribonucleases / Q000494:pharmacology; D004967:Estrogens / Q000494:pharmacology; D005260:Female; D010447:Peptide Hydrolases / Q000494:pharmacology; D010740:Phospholipases / Q000494:pharmacology; D011817:Rabbits; D011980:Receptors, Progesterone / Q000378:metabolism*; D012260:Ribonucleases / Q000494:pharmacology; D014599:Uterus / Q000166:cytology / Q000378:metabolism*
D002843:Chromatin; D004967:Estrogens; D011980:Receptors, Progesterone; D003851:Deoxyribonucleases; D010740:Phospholipases; D012260:Ribonucleases; D010447:Peptide Hydrolases