Light emission from tryptophan oxidation by hypobromous acid

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dc.contributor.authorPetrônio, Maicon Segalla [UNESP]
dc.contributor.authorXimenes, Valdecir Farias [UNESP]
dc.contributor.institutionUniversidade Estadual Paulista (Unesp)
dc.date.accessioned2014-05-27T11:27:06Z
dc.date.available2014-05-27T11:27:06Z
dc.date.issued2012-10-08
dc.description.abstractThe emission of ultraweak light from cells is a phenomenon associated with the oxidation of biomolecules by reactive oxygen species. The indole moiety present in tryptophan, serotonin and melatonin is frequently associated with the emission of light during the oxidation of these metabolites. This study presents results for hypobromous acid (HOBr) oxidation of tryptophan as a putative endogenous source of ultraweak light emission. We found that chemiluminescence elicited by the oxidation of tryptophan by HOBr was significantly higher than by hypochlorous acid (HOCl). This difference was related to secondary oxidation reactions, which were more intense using HOBr. The products identified during oxidation by HOCl, but depleted by using HOBr, were N-formylkynurenine, kynurenine, 1,2,3,3a,8,8a-hexahydro-3a-hydroxypyrrolo[2,3-b]-indole-2-carboxylic acid, oxindolylalanine and dioxindolylalanine. The emission of light is dependent on the free α-amino group of tryptophan, and hence, the indole of serotonin and melatonin, although efficiently oxidized, did not produce chemiluminescence. The emission of light was even greater using taurine monobromamine and dibromamine as the oxidant compared to HOBr. A mechanism based on bromine radical intermediates is suggested for the higher efficiency in light emission. Altogether, the experimental evidence described in the present study indicates that the oxidation of free tryptophan or tryptophan residues in proteins is an important source of ultraweak cellular emission of light. This light emission is increased in the presence of taurine, an amino acid present in large amounts in leukocytes, where this putative source of ultraweak light emission is even more relevant.en
dc.identifierhttp://dx.doi.org/10.1002/bio.2445
dc.identifier.citationLuminescence.
dc.identifier.doi10.1002/bio.2445
dc.identifier.issn1522-7235
dc.identifier.issn1522-7243
dc.identifier.lattes4066413997908572
dc.identifier.scopus2-s2.0-84866931839
dc.identifier.urihttp://hdl.handle.net/11449/73655
dc.identifier.wosWOS:000328577800008
dc.language.isoeng
dc.relation.ispartofLuminescence
dc.relation.ispartofjcr1.671
dc.relation.ispartofsjr0,396
dc.relation.ispartofsjr0,396
dc.rights.accessRightsAcesso restrito
dc.sourceScopus
dc.subjectChemiluminescence
dc.subjectHypobromous acid
dc.subjectHypochlorous acid
dc.subjectTaurine bromamine
dc.subjectTaurine dibromamine
dc.subjectTryptophan
dc.titleLight emission from tryptophan oxidation by hypobromous aciden
dc.typeArtigo
dcterms.licensehttp://olabout.wiley.com/WileyCDA/Section/id-406071.html
unesp.author.lattes4066413997908572
unesp.author.orcid0000-0003-2636-3080[2]
unesp.campusUniversidade Estadual Paulista (Unesp), Faculdade de Ciências Farmacêuticas, Araraquarapt
unesp.campusUniversidade Estadual Paulista (Unesp), Faculdade de Ciências, Baurupt

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Artigos - Química - FC
Artigos - Análises Clínicas - FCFAR