IIBBA   05544
INSTITUTO DE INVESTIGACIONES BIOQUIMICAS DE BUENOS AIRES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
POLYMER-ASSISTED AGGREGATION OF 2-CYS PEROXIREDOXIN FROM RAPESEED (Brassica napus)
Autor/es:
RIMMAUDO L; ARAN M; FERRERO D; WOLOSIUK RA
Lugar:
San Miguel de Tucumán, Tucumán
Reunión:
Congreso; XLV SAIB ANNUAL MEETING; 2009
Institución organizadora:
Sociedad Argentina de Investigación en Bioquímica y Biología Molecular
Resumen:
Typical 2-Cys Peroxiredoxins (2-Cys Prx) are ubiquitous peroxidases that possess two conserved cysteines involved in the detoxification of reactive oxygen species and redox signaling. The composition of the milieu drives the partition of 2-Cys Prx into dimers, decamers and high molecular mass oligomers. Although a key to understanding the biological significance of the quaternary structure is the characterization of the assembly mechanism, factors that prompt 2-Cys Prx out of the solution are barely known. We found that ATP causes the reversible oligomerization of rapeseed 2-Cys Prx decamers (subunit molecular mass: 240 KDa) into species of large molecular masses (> 2 MDa). Searching for alternative modulators in these studies, we analyzed the aggregation of rapeseed 2-Cys Prx mediated by supramolecular structures. We found that critical concentrations of assemblies bearing positive charges cause the precipitation of the protein. Moreover, these results suggest that 2-Cys Prx decamers undergo conformational changes leading to a higher content of â-sheet, which causes a higher propensity to precipitate. The characterization of the driving forces behind the aggregate formation and the structural motifs necessary for the precipitation can help to develop efficient strategies directed to find ways of preventing and healing pathologies related to conformational diseases.