. 2010 Jan 30;1(2):92–103.

Table 1.

Interaction of tamoxifen metabolites with estrogen receptors and steroid sulfatase

	Estrogen Receptor Binding		Inhibition of Steroid Sulfatase Activity
Ligand	^* % Binding affinity for ERα (%, SD)	^* % Binding affinity for ERβ (%, SD)	Incubation conditions	Estrone (pmol min^-1 mg protein^-1)	4-OH-TAM (pmol min^-1 mg protein^-1)
Estradiol	100 (ref)	100 (ref)	Estrone-sulfate, no enzyme	nd	nd
4-OH-TAM	153.8 ± 12.3	59.2 ± 4.7	Estrone-sulfate + HLM	123.1 ± 7.7	nd
SO₄-TAM	1.8 ± 0.4	nd	Estrone-sulfate + HLM + 100 μM SO₄-TAM	118 ± 15.6	nd

percent compared to estradiol; SD from 3 independent measurements.

nd = not detectable