Characterization of the effect of sodium molybdate and diisopropylfluorophosphate on the human myometrial estrogen and progesterone receptors.
The human myometrial estrogen receptor (ER) and progesterone receptor (PR) are stabilized in the presence of 25 mM molybdate. The stabilizing effect is very palpable for the PR; even after 15 min of incubation at 37 degrees C only 15% of the binding activity is lost in the presence of molybdate, whereas during the same period of time 75% of the binding activity is lost in the absence of molybdate. In the presence of molybdate the ER yield is increased by 27.7 +/- 16.3% (mean +/- SD) and the yield of PR is increased by 34.3 +/- 18.3%. Also in the presence of 2 mM diisopropylfluorophosphate (DFP) the PR yield is increased by 25.5 +/- 16.7% whereas the ER recovery is decreased by 22.7 +/- 12.8%. The DNA-binding activities of ER and PR are greatly enhanced in the presence of DFP whereas this activity is blocked by molybdate. No shifts in the sedimentation values of either ER or PR was observed in the presence of molybdate as compared to the sedimentation values obtained in the presence of DFP. Also the equilibrium dissociation constants of ER and PR bindings were not affected by molybdate. DFP however caused a decrease in both the affinity and the binding capacity of the ER whereas the binding characteristics of the PR remained unchanged.
D003600:Cytosol / Q000378:metabolism; D005260:Female; D006801:Humans; D007531:Isoflurophate / Q000494:pharmacology*; D007700:Kinetics; D008982:Molybdenum / Q000494:pharmacology*; D009215:Myometrium / Q000187:drug effects / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism*; D014599:Uterus / Q000378:metabolism*
D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D007531:Isoflurophate; D008982:Molybdenum; C024687:sodium molybdate(VI)