Functional characterization of methionine sulfoxide reductase A from Trypanosoma spp.
Methionine is an amino acid susceptible to being oxidized to methionine sulfoxide (MetSO). The reduction of MetSO to methionine is catalyzed by methionine sulfoxide reductase (MSR), an enzyme present in almost all organisms. In trypanosomatids, the study of antioxidant systems has been mainly focused on the involvement of trypanothione, a specific redox component in these organisms. However, no information is available concerning their mechanisms for repairing oxidized proteins, which would be relevant for the survival of these pathogens in the various stages of their life cycle. We report the molecular cloning of three genes encoding a putative A-type MSR in trypanosomatids. The genes were expressed in Escherichia coli, and the corresponding recombinant proteins were purified and functionally characterized. The enzymes were specific for L-Met(S)SO reduction, using Trypanosoma cruzi tryparedoxin I as the reducing substrate. Each enzyme migrated in electrophoresis with a particular profile reflecting the differences they exhibit in superficial charge. The in vivo presence of the enzymes was evidenced by immunological detection in replicative stages of T. cruzi and Trypanosoma brucei. The results support the occurrence of a metabolic pathway in Trypanosoma spp. involved in the critical function of repairing oxidized macromolecules.
Instituto de Agrobiotecnología del Litoral, UNL-CONICET, 3000 Santa Fe, Argentina.
Diego G
DG
Arias
Matías S
MS
Cabeza
Esteban D
ED
Erben
Pedro G
PG
Carranza
Hugo D
HD
Lujan
María T
MT
Téllez Iñón
Alberto A
AA
Iglesias
Sergio A
SA
Guerrero
D000595:Amino Acid Sequence; D000818:Animals; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D050216:Metabolic Detoxication, Phase I / Q000235:genetics; D053858:Metabolic Networks and Pathways / Q000235:genetics; D051150:Methionine Sulfoxide Reductases / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000235:genetics; D017385:Sequence Homology; D014345:Trypanosoma / Q000201:enzymology* / Q000235:genetics; D014346:Trypanosoma brucei brucei / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D014349:Trypanosoma cruzi / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D014709:Vero Cells
D051150:Methionine Sulfoxide Reductases