Artigo
Recycling of the High Valence States of Heme Proteins by Cysteine Residues of Thimet-Oligopeptidase
Fecha
2013-11-01Registro en:
Plos One. San Francisco: Public Library Science, v. 8, n. 11, 16 p., 2013.
1932-6203
WOS000326499300055.pdf
10.1371/journal.pone.0079102
WOS:000326499300055
Autor
Ferreira, Juliana C. [UNIFESP]
Icimoto, Marcelo Y. [UNIFESP]
Marcondes, Marcelo F. [UNIFESP]
Oliveira, Vitor [UNIFESP]
Nascimento, Otaciro R.
Nantes, Iseli L.
Institución
Resumen
The peptidolytic enzyme THIMET-oligopeptidase (TOP) is able to act as a reducing agent in the peroxidase cycle of myoglobin (Mb) and horseradish peroxidase (HRP). the TOP-promoted recycling of the high valence states of the peroxidases to the respective resting form was accompanied by a significant decrease in the thiol content of the peptidolytic enzyme. EPR (electron paramagnetic resonance) analysis using DBNBS spin trapping revealed that TOP also prevented the formation of tryptophanyl radical in Mb challenged by H2O2. the oxidation of TOP thiol groups by peroxidases did not promote the inactivating oligomerization observed in the oxidation promoted by the enzyme aging. These findings are discussed towards a possible occurrence of these reactions in cells.