binding of agonists and antagonists

The effect of aldosterone and antimineralocorticoids on the intracellular localization of human mineralocorticosteroid receptor (hMR) was studied using a new monoclonal anti-peptide antibody FD4. This antibody was directed against the peptide hMR-(412-422). As demonstrated by ultracentrifugation analysis, immunoprecipitation assays and Western blot, FD4 recognized both the native and denatured form of the receptor overexpressed in the baculovirus expression system. In whole-cell assays, the amount of hMR recovered in high-salt extracts was significantly lower after exposure to the antimineralocorticoid ZK91587 than to aldosterone, suggesting a lack of nuclear MR translocation. FD4 was also used for immunohistochemical studies on hMR-expressing High Five cells. In the absence of hormone, immunoreactive hMR was detected almost exclusively