Influence of proteinase inhibitors on glucocorticoid receptor binding.
The influence of several proteinase inhibitors on rat liver cytosolic glucocorticoid receptor binding to [3H]triamcinolone acetonide has been investigated. E-64 (36 microM), an active-site directed cysteine proteinase inhibitor, significantly (about 40%) inhibited receptor binding. Tos-Lys-CH2Cl (1-2 mM) and Tos-Phe-CH2Cl (1-2 mM) also depressed receptor binding (20-67%). Interestingly, 5 mM dithiothreitol was able to prevent Tos-Lys-CH2Cl and Tos-Phe-CH2Cl effects, but had no apparent influence on E-64 action. A degree of proteinase inhibitor specificity was indicated by the lack of effect of several other proteinase inhibitors such as diisopropylfluorophosphate (1 mM), phenylmethylsulfonyl fluoride (1-2 mM), soybean trypsin inhibitor (1-2 mg/ml), tissue inhibitor of metalloproteinase (3.8 U/ml), cystatin (4-8 microM), and phosphoramidon (20-40 microM). These results suggest that thiol reactive proteinase inhibitors block glucocorticoid receptor binding, and that E-64 may prove to be a useful chemical probe in studying glucocorticoid receptor interaction.
D000818:Animals; D003600:Cytosol / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D008297:Male; D011480:Protease Inhibitors / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011965:Receptors, Glucocorticoid / Q000187:drug effects / Q000378:metabolism*; D011987:Receptors, Steroid / Q000378:metabolism*; D013329:Structure-Activity Relationship; D014222:Triamcinolone Acetonide / Q000378:metabolism
D011480:Protease Inhibitors; D011965:Receptors, Glucocorticoid; D011987:Receptors, Steroid; D014222:Triamcinolone Acetonide