Poster - ?Leptospira interrogans has glutathione metabolism?.

SASONI, N; FERRERO, DML; GUERRERO, SA; IGLESIAS, AA; ARIAS, DG

Paraná

Congreso; SAIB LIV Reunión Anual; 2018

SAIB

Glutathione (GSH) is the most abundant lowmolecular mass thiol in almost all eukaryotic cells, as well as in proteo andcyanobacteria. It is synthesized enzymatically in two ATP-Mg2+dependentsteps: first, glutamate cysteine ​​ligase (GCL) establishes a peptide bondbetween cysteine ​​and glutamate, forming γ-glutamylcysteine ​​(γ-GC). Second,glutathione synthetase (GS, which is a member of ATP-Grasp superfamily) addsglycine residue to the carboxy terminus of γ‑GC, producing GSH. Until now,there is not information available to shows the presence of GSH metabolism in L. interrogans (the causative agentof leptospirosis). In this work, we present the recombinant expression andfunctional characterization of LinGCLand LinATPGrasp, responsible for GSH synthesisin this pathogen bacterium. LinGCLshowed higher substrate promiscuity than LinATPGraspand its enzymatic activity was inhibited by γ-GC and GSH. GSH has alsoinhibited LinATPGrasp but with a lowereffect. Finally, we measured the activity of these enzymes and the GSH content inbacterial cell extract. These measurements indicated a higher GSH level in L. interrogans than in L. biflexa (free-living bacteria). Thelast result would help explain the virulence of L. interrognas and indicate the GSH role as part its antioxidant metabolism.