TABLE 3.

Molecular Modeling of Ligand Interaction with Human, Mouse, and Trout ERα LBDs

	ICM docking score			Hydrogen-bonding interactions
Ligand	hERα	mERα	rtERα1	HERα	mERα	rtERα	Classificationa
E2	−38.68	−37.75	−36.34	R394, E353, H524	R398, E357, H528	R407, E366, H537	S
DES	−38.34	−37.40	−37.25	R394, E353, H524	R398, E357, H528	R407, E366, H537	S
GEN	−30.10	−32.70	−31.63	R394, L387, H524	R398, L391, H528	R407, L400, H537	M
NP	−23.41	−24.49	−23.39	R394, L387	R398, L391	R407, L400	W
BPA	−18.77	−27.86	−17.34	E353, H524	R398, E357, T351	E366	M,W
PFHpA	−6.95	−9.63	−8.64	R394	R398, E357	R407	VW
PFOA	−11.84	−17.75	−11.70	R394	R398, L391	R407	VW
PFNA	−13.96	−22.54	−16.45	R394	R398	R407	VW,W
PFDA	−18.77	−20.05	−13.41	R394	R398	R407	VW,W
PFUnDA	−11.87	−17.85	−12.60	R394	R398	R407	VW,W
PFOS	−15.77	−19.06	−10.96	R394	R398	R407	VW,W
PFDS	−11.52	−14.79	−11.12	R394	R398	R407	VW
6:2FtOH	−20.48	−20.46	−20.30	R394, E353	R398	R407, E366	W
8:2FtOH	−18.57	−25.68	−18.06	R394, L387	R398	R407, L400	W
8:2FtOAcr	−15.60	−14.50	−17.06	R394	R398	R407	W

Note. ICM scores are a measure of fit within the receptor-binding pocket, taking into account continuum and discreet electrostatics, hydrophobicity, and entropy parameters. The predicted amino acid residue locations for hydrogen bonding are indicated for each ligand-protein docking.

^aLetters indicate classification of ICM docking scores into four broad groups indicating predicted affinity for ERα as follows: S, strong affinity (ICM scores > −35); M, moderate affinity (scores −25 and −35); W, weak affinity (scores −15 to −25); and VW, very weak affinity (scores > −15). Two classifications are given when scores for different receptors fit within multiple ranges.