Poster - ?Functional characterization of a glutaredoxin-like protein from Entamoeba histolytica?.

BIROCCO, F; SASONI, N; GUERRERO, SA; IGLESIAS, AA; ARIAS, DG

Paraná

Congreso; SAIB LIV Reunión Anual; 2018

SAIB

Entamoeba histolytica, an intestinal parasitic protozoan, is thecausative agent of amoebiasis. Theparasite usually lives and multiplies within the human gut, an environment ofreduced oxygen pressure. During tissue invasion, E. histolytica isexposed to elevated amounts of exogenous reactive oxygen species (ROS), whichare highly toxic for the parasite. The metabolic pathway for ROS detoxificationin this organism is a matter of controversy. Because neither glutathione norits associated enzymes were found to occur, it has been proposed the cysteineas a main intracellular thiol and one of the compounds responsible for  maintaining the intracellular redox balance. Nevertheless,we report in this work the discovery of a glutaredoxin-like protein encoded in E.histolytica genomethrough bioinformatic technique. We present the molecularcloning from E. histolytica genomic DNA of an encodinggene for monothiol glutaredoxin-like protein (EhGRX1). The clonedgene was expressed in Escherichia coli, and the correspondingrecombinant protein was purified chromatographically and characterized. The recombinant protein catalysed GSH-dependant low molecular disulfide reduction.No synergistic effect of EhGRX1with thioredoxin system in low molecular mass disulfide reduction was observed.Treatment with different oxidants was carried out and its oligomeric state was revealedby non-reducing SDS-PAGE and gel filtration chromatography. The protein wasdetected in trophozoites by western blot experiments. To the best of our knowledge this is the first characterization of this type of protein in E. histolytica.