“The effects of copper ions on the binding of steroids to receptors revealed that the inhibitory effect of Cu++ was apparent at 10(-6)M, ANd the binding capacities decreased to 10% at 10(-2)M Cu++.”
“The kinetic study demonstrated that Cu++ was a competitive inhibitor of steroid hormone-receptor binding (Ki divided by 2.7 X 10(-5)M to estrogen receptor; Ki divided by 5.1 X 10(-6)M to progesterone receptor).”