FUNCTIONAL CHARACTERIZATION OF A GLUTAREDOXIN-LIKE PROTEIN FROM Entamoeba histolytica

BIROCCO, F.; SASONI, N; GUERRERO, SERGIO A.; IGLESIAS, ALBERTO A.; ARIAS, DIEGO G.

Paraná

Congreso; LIV Annual meeting Argentina Society for Biochemistry and Molecular Biology; 2018

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular y Pan-American Association for Biochemistry and Molecular Biology

Entamoeba histolytica, an intestinal parasitic protozoan, is the causative agent of amoebiasis. The parasite usually lives and multiplies within thehuman gut, an environment of reduced oxygen pressure. During tissue invasion, E. histolytica is exposed to elevated amounts of exogenousreactive oxygen species (ROS), which are highly toxic for the parasite. The metabolic pathway for ROS detoxification in this organism is amatter of controversy. Because neither glutathione nor its associated enzymes were found to occur, it has been proposed the cysteine as a mainintracellular thiol and one of the compounds responsible for maintaining the intracellular redox balance. Nevertheless, we report in this work thediscovery of a glutaredoxin-like protein encoded in E. histolytica genome through bioinformatic techniques. We present the molecular cloningfrom E. histolytica genomic DNA of an encoding gene for monothiol glutaredoxin-like protein (EhGRX1). The cloned gene was expressed inEscherichia coli, and the corresponding recombinant protein was purified by chromatography and characterized. The recombinant proteincatalyzed GSH-dependent low molecular disulfide reduction. No synergistic effect of EhGRX1 with thioredoxin system in low molecular massdisulfide reduction was observed. Treatment with different oxidants was carried out and its oligomeric state was revealed by non-reducing SDSPAGE and gel filtration chromatography. The protein was detected in trophozoites by western blot experiments. To the best of our knowledgethis is the first characterization of this type of protein in E. histolytica.Granted by ANPCyT (PICT2014-2103 and PICT2016-1778)