Table 1

Binding of the peptide probe to ER α and ER β in the presence of modulators

ModulatorEC50 for ER peptide probe
ER α ER β
α/β Iα/β IIIα/β IVα/β Vα IIα/β Iα/β IIIα/β IVα/β Vβ Iβ III
Buffer
17β-Estradiol818817226271317
Estriol81945122016122112
4-OH tamoxifen5560314237180502134
Nafoxidine29037039230320
Clomiphene14071028012082150140120
Raloxifene49429090160
ICI 182, 78026252918352948
Diethylstilbesterol1330163415181125
  • EC50 is defined as the concentration, in nanomolar, of a given modulator required to achieve a 50% change in the binding of the probe to the receptor. The change in conformation may result in an increase or decrease in the affinity of the probe for the receptor.