Formation of a fluorescent glucocorticoid receptor-steroid complex in HTC cell cytosol.
An intensely fluorescent rhodamine derivative of dexamethasone (i.e. Dex-C2-Rho) was synthesized. Dex-C2-Rho possessed high affinity for HTC cell glucocorticoid receptors in cell-free systems. Whole cell activity and receptor affinity of Dex-C2-Rho were both much lower, apparently due to problems with cell permeability and/or metabolism. A specific, fluorescent receptor-steroid complex at concentrations as low as 1 X 10(-9) M could readily be observed with crude HTC cell receptors after removal of the free Dex-C2-Rho. This appears to be the first report of a fluorescent glucocorticoid receptor-steroid complex.
D000818:Animals; D001667:Binding, Competitive; D002474:Cell-Free System; D046508:Culture Techniques; D003600:Cytosol / Q000378:metabolism; D003907:Dexamethasone / Q000031:analogs & derivatives* / Q000378:metabolism; D008114:Liver Neoplasms, Experimental / Q000378:metabolism*; D051381:Rats; D011965:Receptors, Glucocorticoid / Q000378:metabolism*; D012235:Rhodamines / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D014966:Xanthenes / Q000378:metabolism*
D011965:Receptors, Glucocorticoid; D012235:Rhodamines; D014966:Xanthenes; D003907:Dexamethasone; C046763:N-(dexamethasone 21-S-ethyl-2'-amino)tetramethylrhodamine