Binding of chlorpromazine to S-100 protein.
Chlorpromazine (CPZ) induces in S-100 conformational changes resulting in the exposure of titratable SH groups of the protein to the solvent. This effect is even greater in the presence of Mg2+ +/- Ca2+. S-100 possesses binding sites for CPZ. The binding of CPZ to 3 microM S-100 is half-saturated by 0.18 microM CPZ in the presence of Mg2+ plus Ca2+ and by 0.24 microM CPZ in the presence of Mg2+ plus EGTA. The extent of the binding is greater in the presence of Ca2+ than in the presence of EGTA, especially at low CPZ concentrations.
D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002417:Cattle; D002746:Chlorpromazine / Q000378:metabolism*; D004228:Dithionitrobenzoic Acid / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D011485:Protein Binding; D011487:Protein Conformation; D009418:S100 Proteins / Q000378:metabolism*
D009418:S100 Proteins; D004533:Egtazic Acid; D004228:Dithionitrobenzoic Acid; D008274:Magnesium; D002118:Calcium; D002746:Chlorpromazine