Ascorbate peroxidase-thioredoxin interaction.
Photosynth Res
; 89(2-3): 193-200, 2006 Sep.
Article
em En
| MEDLINE
| ID: mdl-17031543
ABSTRACT
Proteomics data have suggested ascorbate peroxidase (APX) to be a potential thioredoxin-interacting protein. Using recombinant enzymes, we observed that incubation of pea cytosolic APX with reduced poplar thioredoxins h drastically inactivated the peroxidase. A similar inactivation is induced by reduced glutathione and dithiothreitol, whereas diamide and oxidized glutathione have no effect. Oxygen consumption measurements, modifications of the APX visible spectrum and protection by hydrogen peroxide scavenging enzymes suggest that APX oxidizes thiols leading to the generation of thiyl radicals. These radicals can in turn react with thiyl anions to produce the disulfide radical anions, which are responsible for oxygen reduction and subsequent hydrogen peroxide production. The APX inactivation is not due solely to hydrogen peroxide since fluorimetry indicates that the environment of the APX tryptophan residues is dramatically modified only in the presence of thiol groups. The physiological implications of this interaction are discussed.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Peroxidases
/
Tiorredoxinas
Idioma:
En
Revista:
Photosynth Res
Assunto da revista:
METABOLISMO
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
França