Table 1

Stability of the wild type and mutated VDR LBDs against limited proteolytic digestion with trypsin

Location in VDR	Mutated VDRs	20-Normal Compounds		20-epi Compounds
Location in VDR	Mutated VDRs	Calcitriol	VD 2708	VD 2728	MC 903	EB 1089	MC 1288	VD 2668	GS1 500	VD 2656	KH1 060	CB1 260	CB 1393	MC1 598	CB1 093	HEP 187	CB 1016
C	Y143A	⁺	⁺	⁺	–	–	⁺	⁺	–	–	⁺	–	⁺	–	⁺	–	–
	R158A	⁺	⁺	⁺	⁺	–	⁺	⁺	⁺	⁺	⁺	⁺	⁺	⁺	⁺	⁺	–
H3	H229A	–	⁺	–	–	–	⁺	–	–	–	⁺	–	–	⁺	–	–	–
	D232A	–	⁺	–	–	–	⁺	–	–	–	⁺	–	–	⁺	–	–	–
	V234A	⁺	⁺	⁺	⁺	–	⁺	⁺	⁺	–	⁺	⁺	⁺	⁺	⁺	⁺	⁺
	S235A	⁺	⁺	⁺	⁺	⁺	⁺	⁺	⁺	⁺	⁺	–	–	–	⁺	⁺	⁺
	Y236A	–	–	⁺	–	–	⁺	–	–	–	–	–	–	⁺	–	–	–
	S237A	–	⁺	–	–	–	⁺	–	–	–	⁺	–	–	⁺	⁺	–	–
H5	E269A	–	⁺	⁺	⁺	–	⁺	–	⁺	–	⁺	–	⁺	⁺	⁺	–	–
	S275A	⁺	⁺	⁺	–	⁺	⁺	–	⁺	–	⁺	–	⁺	⁺	⁺	⁺	–
	S278A	⁺	⁺	⁺	⁺	–	⁺	⁺	⁺	–	⁺	⁺	⁺	⁺	⁺	–	–
H6	D299A	⁺	⁺	⁺	–	–	⁺	–	⁺	–	⁺	–	⁺	⁺	⁺	–	–
C	H305A	⁺	–	⁺	⁺	⁺	–	–	⁺	⁺	⁺	–	–	⁺	–	–	–

(−)-Ligand treatment stabilizes the LBD by less than 20% of that of the wild-type VDR; (⁺)-ligand treatment stabilizes the LBD by more than 20% of that of the wild-type VDR. Locations of mutated amino acids within VDR are indicated as coil (C) or helix (H).