| Texto completo | |
| Autor(es): |
Cerchiaro, Giselle
;
Bolin, Celeste
;
Cardozo-Pelaez, Fernando
Número total de Autores: 3
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Redox Report; v. 14, n. 2, p. 11-pg., 2009-04-01. |
| Resumo | |
Levels of oxidized guanosine base in DNA have become a hallmark biomarker in assessing oxidative stress implicated in a variety of disease and toxin-induced states. However, there is evidence that the guanosine in the nucleotide triphosphate pool (GTP) is more susceptible to oxidation than guanosine residues incorporated into nucleic acids and this causes a substantial amount of the oxidized product, 8-oxoguanosine 5'-triphosphate (oxo(8)GTP), to accumulate in cell-free and in cell-culture preparations. Electron paramagnetic resonance (EPR) spectroscopy and direct EPR analysis of free radical production by copper sulfate and L-ascorbic acid demonstrates that the hydroxy. radical (HO center dot) is produced via oxidation of Cu+ to Cu2+ while in a complex with GTP. This HO center dot production is dependent on the availability of oxygen and the presence of GTP in the reaction milieu. Verification of free radical-mediated production of oxo(8)GTP is presented using HPLC with electrochemical detection and matrix-assisted laser desorption/ionization linear time-of-flight mass spectrometry (MALDI-LTOF-MS). The sum of these results is presented in a novel mechanism of GTP oxidation by Cu2+ and L-ascorbic acid. A better understanding of the chemistry involved in this oxidative modification of GTP facilitates a more comprehensive understanding of its potentia. physiological consequences. (AU) | |
| Processo FAPESP: | 07/50765-2 - Estudo de processos oxidativos e radicalares envolvendo o cobre no meio biológico: uma investigação de mecanismos moleculares da atividade oxidante de complexos e proteínas contendo cobre |
| Beneficiário: | Giselle Cerchiaro |
| Modalidade de apoio: | Auxílio à Pesquisa - Jovens Pesquisadores |