title: In vitro interaction of organic copper (II) compounds with soluble glutathione S-transferases from rat liver.
abstract: The in vitro interaction of organic copper (II) compounds with rat liver glutathione S-transferases (GST) was studied using reduced glutathione (GSH) and 1-chloro-2,4-dinitrobenzene (CDNB) as substrates. The inhibition of the GST activity was dose dependent. The different GST isoenzymes were inhibited to different degrees. Kinetic studies never revealed competitive inhibition. Titration of remaining GSH in appropriate incubation mixtures with organic copper (II) compounds revealed no GST catalyzed conjugation of these compounds with GSH. These experiments showed a spontaneous conjugation of the copper (II) compounds with GSH, explaining the parabolic inhibition observed in the kinetic studies with GSH as the variable substrate. Both organic and inorganic copper (II) are spontaneously conjugated with GSH, but interact with GST by direct binding to these proteins. This binding could have a protective function against copper (II).
mesh_terms: D000818:Animals; D003300:Copper / Q000378:metabolism* / Q000494:pharmacology; D004137:Dinitrochlorobenzene; D005982:Glutathione Transferase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D005998:Glycine / Q000378:metabolism / Q000494:pharmacology; D066298:In Vitro Techniques; D008658:Inactivation, Metabolic; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D008698:Mesylates / Q000378:metabolism / Q000494:pharmacology; D009942:Organometallic Compounds; D051381:Rats
chemical_list: D004137:Dinitrochlorobenzene; D007527:Isoenzymes; D008698:Mesylates; D009942:Organometallic Compounds; C015092:cupric acetate; C018493:cupric glycinate; D003300:Copper; D005982:Glutathione Transferase; C012077:trifluoromethanesulfonic acid; C029892:cupric chloride; D005998:Glycine