The calcium sensor ruthenium red can act as a fenton-type reagent

dc.creatorMeinicke, AR
dc.creatorZavan, SS
dc.creatorFerreira, AMC
dc.creatorVercesi, AE
dc.creatorBechara, EJH
dc.date1996
dc.dateAPR 15
dc.date2014-12-16T11:31:58Z
dc.date2015-11-26T17:50:10Z
dc.date2014-12-16T11:31:58Z
dc.date2015-11-26T17:50:10Z
dc.date.accessioned2018-03-29T00:33:21Z
dc.date.available2018-03-29T00:33:21Z
dc.identifierArchives Of Biochemistry And Biophysics. Academic Press Inc Jnl-comp Subscriptions, v. 328, n. 2, n. 239, n. 244, 1996.
dc.identifier0003-9861
dc.identifierWOS:A1996UE73600004
dc.identifier10.1006/abbi.1996.0169
dc.identifierhttp://www.repositorio.unicamp.br/jspui/handle/REPOSIP/78102
dc.identifierhttp://www.repositorio.unicamp.br/handle/REPOSIP/78102
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/78102
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1289602
dc.descriptionRuthenium red (RR), an ammoniated form of tris-ruthenium(III,IV,III) oxychloride, has been widely used in the micromolar range as a strong and specific inhibitor of in vitro and in vivo Ca2+-mediated biochemical processes without regard for its redox properties. We show here that in the presence of tert-butyl hydroperoxide (TBHP) and an electron source, either succinate-energized rat Liver mitochondria or ascorbate, RR amplifies the generation of methyl radicals. The EPR spin trapping signal of the 5,5-dimethyl-1-pyrroline-N-oxide/methyl radical (DMPO/(CH3)-C-.) adduct obtained from incubations of TBHP (1.5 mM) and mitochondria (5 mg protein/ml) in an adequate medium increases upon addition of RR in a concentration-dependent fashion: sixfold at 10 mu M RR. Respiring mitochondria can be replaced by ascorbate (1 mM), the characteristic EPR signal of the ascorbyl radical also being observed (a(H) = 0.18 mT). Spectrophotometric, cyclic voltammetric and spectroelectrochemical studies unequivocally show oxidation of RR(III,IV,III) (lambda(max) = 538 nm) to the ruthenium(IV,III,IV) species ('ruthenium brown,' RB; lambda(max) = 464 nm) by TBHP, followed by its one-electron back reduction to RR by the respiratory chain or ascorbate. The calcium chelator EGTA (1 mM) strongly binds and stabilizes the RR form, slowing down its recycling by TBHP and either ascorbate or the mitochondrial electron chain. These data clearly show that Ru-III in the RR complex can reduce TBHP via a Fenton-type reaction and thus must be considered when RR is used as a tool to study biological processes simultaneously involving Ca2+ ions and peroxides. (C) 1996 Academic Press, Inc.
dc.description328
dc.description2
dc.description239
dc.description244
dc.languageen
dc.publisherAcademic Press Inc Jnl-comp Subscriptions
dc.publisherSan Diego
dc.relationArchives Of Biochemistry And Biophysics
dc.relationArch. Biochem. Biophys.
dc.rightsfechado
dc.sourceWeb of Science
dc.subjectruthenium red
dc.subjecttert-butyl hydroperoxide
dc.subjectrat liver mitochondria
dc.subjectreactive oxygen species
dc.subjectRat-liver Mitochondria
dc.subjectPyruvate-dehydrogenase
dc.subjectCorn Mitochondria
dc.subjectOxidation-states
dc.subjectTransport
dc.subjectCa-2+
dc.subjectInhibition
dc.subjectActivation
dc.subjectComplexes
dc.subjectHeart
dc.titleThe calcium sensor ruthenium red can act as a fenton-type reagent
dc.typeArtículos de revistas


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