FIG. 6.

(A) Coomassie blue-stained extracts from E. coli programmed with empty vector (pQE8 or pCAL) and receptor-expressing plasmids (RXRα, TRβ1, TRβ3, and TRΔβ3). Expressed receptors were purified by Ni-nitrilotriacetate-agarose (pQE8 and RXRα) or calmodulin (pCAL and TRs) column chromatography. Asterisks show receptor fusion proteins of the appropriate sizes. (B) Western blotting with a monoclonal antibody to amino acids 235 to 414 of TRβ, showing expression of full-length β1, β3, and Δβ3 fusion proteins.