GIRARDINI BROVELLI Javier Enrique
Characterization of an omega-class glutathione S-transferase from Schistosoma mansoniwith glutaredoxin-like dehydroascorbate reductase and thiol transferase activities
GIRARDINI J.E.; AMIRANTE A.; ZEMZOUMI K; SERRA E.
EUROPEAN JOURNAL OF BIOCHEMISTRY
Año: 2002 vol. 269 p. 5512 - 5521
Glutathione S-transferases (EC 18.104.22.168) (GSTs), are afamily of multifunctional enzymes present in all livingorganisms whose main function is the detoxification ofelectrophilic compounds. GSTs are considered the mostprominent detoxifying class II enzymes in helminths. Wedescribe here the characterization of novel dehydroascorbatereductase and thiol transferase activities that reside in thehuman parasite Schistosoma mansoni GSTx. Proteinsequence analysis of this parasite product showed loweridentity to known GSTs. However, phylogenic analysisplaced SmGSTx among the recently described omega classGSTs (GSTO1-1).Wereport here that SmGSTOprotein is a28-kDa polypeptide, detected in all life stages of the parasite,being highly expressed in adult worms. Like other omegaclass GSTs, SmGSTO showed very low activity towardclassical GSTs substrates as 1-chloro-2,4-dinitrobenzene,and no binding affinity to glutathioneagarose matrix butshowed some biochemical characteristics related with thioredoxins/glutaredoxins. Interestingly, SmGSTO was able tobind S-hexyl glutathione matrix and displayed significantglutathione-dependent dehydroascorbate reductase andthiol transferase enzymatic activities.