Characterization of Thioredoxin System from Leptospira interrogans

SASONI, NATALIA; REINOSO, ANAHÍ; ARIAS, DIEGO G.; IGLESIAS, ALBERTO A.; GUERRERO, SERGIO A.

Mendoza

Congreso; XLVIII Reunión Anual de la SAIB; 2012

Sociedad Argentina de Investigación Bioquímica y Biología Molecular

During tissue invasion, (the causative agent of leptospirosis) is exposed to elevated amounts of exogenous reactive oxygen and nitrogen species, which are highly toxic for the bacteria. However, this pathogen is able to establish a persistent infection in its human host. The metabolic pathways for redox homeostasis in this organism are poorly understood. In this work, we present the cloning, recombinant expression and functional characterization of the thioredoxin system (thioredoxin, TRX and thioredoxin reductase, TRXR) from . The TRXR (a low molecular massTRXR) was evaluated in its ability to catalyse the NADPH dependent reduction of DTNB and TRX. TRXsystem could be assayed as a functional redox pair that, together with 2Cys typical peroxiredoxin ( 2CysPrx) mediates the NADPH-dependent reduction of hydroperoxides. Moreover, 2CysPrx was able to accept electrons from heterologous thioredoxin system and it was shown to be sensitive to overoxidation by peroxide substrate. This work strongly supports the occurrence ofTRX system in , adding value to the genome project information of this pathogen.