title: Modification of protein by disulfide S-monoxide and disulfide S-dioxide: distinctive effects on PKC.
abstract: Disulfide S-monoxide (DSMO) and disulfide S-dioxide (DSDO) have been proposed as proximal mediators for the oxidant-mediated modification of proteins. These disulfide S-oxides (DSOs) derived from glutathione (GSH) and captopril (CPSH) were synthesized by iron- or methyltrioxorhenium (VII)-catalyzed oxidation of the thiols with H2O2. Treatment of mouse hippocampal extracts with [35S]GS-DSOs revealed that a large number of proteins were susceptible to thionylation; however, only a limited number of the them were detectable by the commonly used antibody against GS-associated proteins. Using protein kinase C (PKC) as a model, we found that DSOs derived from different thiols modified this kinase with different efficacy and specificity; for example, the inhibitory potency of the kinase was glutathione disulfide S-dioxide (GS-DSDO) (IC50, approximately 30 microM) > captopril disulfide S-dioxide (CPS-DSDO) (IC50, approximately 450 microM) > glutathione disulfide S-monoxide (GS-DSMO) and captopril disulfide S-monoxide (CPS-DSMO). The stoichiometries of thionylation of PKC beta mediated by [35S]GS-DSMO and [35S]GS-DSDO were approximately 1 and 5 mol/mol, respectively, and at least four glutathionylation sites were identified in the GS-DSDO-treated kinase. Modification of PKC by GS-DSDO and CPS-DSDO rendered the kinase very susceptible to limited proteolysis; the former preferentially caused the degradation of the catalytic and the latter the regulatory domain of the kinase. Furthermore, CPS-DSDO-mediated modification of PKC increased the autonomous kinase activity; this was not the case for GS-DSDO-mediated modification. Since DSOs of different oxidative states as well as those derived from different thiols exert different effects on a target protein, these molecules could cause distinct cellular responses if derived from endogenous cellular reactions or even if they arise from exogenous sources.
authors.affiliation: Section on Metabolic Regulation, Endocrinology and Reproduction Research Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892-4510, USA. huangk@mail.nih.gov
authors.forename: Kuo-Ping
authors.initials: KP
authors.lastname: Huang
authors.forename: Freesia L
authors.initials: FL
authors.lastname: Huang
authors.forename: Pavan K
authors.initials: PK
authors.lastname: Shetty
authors.forename: Alfred L
authors.initials: AL
authors.lastname: Yergey
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000737:chemistry; D000818:Animals; D002216:Captopril / Q000737:chemistry; D002384:Catalysis; D004220:Disulfides / Q000138:chemical synthesis / Q000378:metabolism / Q000494:pharmacology*; D005290:Ferric Compounds; D005978:Glutathione / Q000737:chemistry; D006624:Hippocampus / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000737:chemistry; D006868:Hydrolysis; D066298:In Vitro Techniques; D051379:Mice; D009942:Organometallic Compounds; D010084:Oxidation-Reduction; D011493:Protein Kinase C / Q000378:metabolism*; D064546:Protein Kinase C beta; D013329:Structure-Activity Relationship; D013450:Sulfones / Q000138:chemical synthesis / Q000378:metabolism / Q000494:pharmacology*; D014020:Tissue Extracts / Q000378:metabolism
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D004220:Disulfides; D005290:Ferric Compounds; D009942:Organometallic Compounds; D013450:Sulfones; D014020:Tissue Extracts; C411866:methyltrioxorhenium VII; D002216:Captopril; D006861:Hydrogen Peroxide; D011493:Protein Kinase C; D064546:Protein Kinase C beta; D005978:Glutathione