Figure 4: Simultaneous binding of EE2 and TNC to PXR.

Mass spectrometry analysis. Non-denaturing ESI-MS was used to characterize PXR LBD (10 μM) in (a) the unliganded form or in the presence of (b) EE2 (20 μM), (c) TNC (20 μM), or (d) a mixture of EE2 (20 μM) and TNC (20 μM). *, acetate adducts; $, fortuitous binders 254-324 Da; , fortuitous binder 254 Da; #, non-specific EE2 adducts.