Conformational changes of the glucocorticoid receptor ligand binding domain induced by ligand and cofactor binding, and the location of cofactor binding sites determined by hydrogen/deuterium exchange mass spectrometry.
HXMS (hydrogen/deuterium exchange mass spectrometry) of the glucocorticoid receptor ligand-binding domain (GR LBD) complexed with the agonist dexamethasone and the antagonist RU-486 is described. Variations in the rates of exchange were observed in regions consistent with the published crystal structures of GR LBD complexed with RU-486 when compared with the GR dexamethasone complex. We also report the HXMS results for agonist-bound GR LBD with the coactivator transcriptional intermediary factor 2 (TIF2) and anatagonist-bound GR LBD with nuclear receptor corepressor (NCoR). Alterations in exchange rates observed for agonist-bound GR LBD with TIF2 present were consistent with the published crystal structural contacts for the complex. Alterations in exchange rates observed for antagonist-bound GR LBD with NCoR were a subset of those observed with TIF2 binding, suggesting a common or overlapping binding site for coactivator and corepressor.
Frego
Lee
L
Boehringer Ingelheim Phramaceuticals, Research and Development Center, Ridgefield, Connecticut 06877, USA. lfrego@rdg.boehringer-ingelheim.com
Davidson
Walter
W
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D018360:Crystallography, X-Ray; D041961:Deuterium Exchange Measurement / Q000379:methods*; D003907:Dexamethasone / Q000819:agonists / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D008024:Ligands; D013058:Mass Spectrometry / Q000379:methods*; D015735:Mifepristone / Q000819:agonists / Q000378:metabolism / Q000494:pharmacology; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism; D056971:Nuclear Receptor Co-Repressor 1; D051958:Nuclear Receptor Coactivator 2 / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation / Q000187:drug effects; D017434:Protein Structure, Tertiary; D011965:Receptors, Glucocorticoid / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism; D012097:Repressor Proteins / Q000737:chemistry / Q000378:metabolism
D008024:Ligands; C498001:NCOA2 protein, human; C539127:NCOR1 protein, human; D009687:Nuclear Proteins; D056971:Nuclear Receptor Co-Repressor 1; D051958:Nuclear Receptor Coactivator 2; D011965:Receptors, Glucocorticoid; D012097:Repressor Proteins; D015735:Mifepristone; D003907:Dexamethasone