21 hemisuccinate 6,19 epoxyprogesterone 21 hydroxy 6,19 epoxyprogesterone Animals COS Cells Cell Line Cercopithecus Cercopithecus aethiops DNA DNA drug complex Dimerization Electrophoretic Mobility Shift Assay Immunoprecipitation Models, Molecular Molecular Dynamics Simulation Protein Binding Receptors, Glucocorticoid Steroids animal article binding affinity cell assay cell culture cell line cell strain BHK cell strain COS1 cell strain COS7 cell strain L 929 cell type chemical structure computer model