Hydrogen/Deuterium exchange (HDX) coupled with mass spectrometry has emerged as a rapid and sensitive approach for characterization of protein folding, protein-protein interactions, and protein-ligand interactions. Our laboratory in particular has driven the application of this technology in the nuclear receptor field.One important example or our work described a novel mechanism of ligand-activation of PPARg where different binding modes were detected for full agonists as compared to partial agonists and that partial agonists activate the receptor in a helix 12-independent fashion relying on stabilization of other regions of the LBP. This work was published in the journal Structure in 2007 (Bruning et al, Structure 2007 15 1258). In collaboration with the Spiegelman lab at Dana Farber, this work has contributed to understanding the mechanism of a cdk5 mediated phosphorylation of PPARG that controls a sub-set of PPAR target genes which are dysregulated in obesity. A manuscript describing this work has been published Nature.It is important to note that protein structure of most PPARg ligand complexes look very similar, yet HDX is able to detect and pinpoint unique features in receptor dynamics.
Other examples from our laboratory include the use of HDX to classify various selective ERa modulators (SERMs) based on their HDX signatures and these signatures were determined to be correlative to the pharmacology observed with these ligands in both pre-clinical and clinical settings. This work was published in PNAS (Dai et al, PNAS 2008).Morerecently, we used HDX to reveal unique binding patterns of estrogens to ERa and ERb(Dai et al, Biochemistry 2009). A manuscript is in Press in the journal Structure focused on HDX of VDR.