Functional Characterization of Methionine Sulfoxide Reductase from Trypanosoma cruzi

D.G. ARIAS; M.S. CABEZA; M.L. ECHARREN; A.A. IGLESIAS; S.A. GUERRERO

Mendoza

Congreso; XLVIII Reunión Anual de la SAIB; 2012

SAIB

hlethionine is an amino acid susceptible to be oxidized tomethionine sulfoxide (MetSO). Reduction aFMetSO to rnethioninei s catalyzed by methimine sulfoxide wductase (MSR), an enzymepresent in almost all organisms In trypanosomatids, the study ofantioxidant systems has baen mainly f ~ ~theo invonlvem ent oftrypanothione, a specific redox component in these organisms.1-Towever, poorly ~nfnrmafion is awilahle cnncemlng theirmechanisms for repalrlng oxidized pmtelns, which would berelevant for the syrvlval nf these pathogens in thevarlovs stages oftheir life cycle. Recently, we characterized two A-type MSRproteins from Z cruzi and T: hmei. In this work, we report themolecular cloning of a gene encoding a putative B type MSR. Thegme was expressed in E. coli, und h e corresponding re~~rnb´iantprotein was purified and functionally characterized. The enzymewas specific for LMet(R)SO reduclian, using Z c& TXNI,TXNll and TRX as the reducing substrates. In addition, we foundthat R4tSRE could compensate Tor MSR deficiency in yeastmutant strain lacking both MSKA and MSRB genes. The proteinprcscnted redox-dependent changc In monornerldimcroligommi7mtion states. Thc rcsulCj supporl thc occumcc of ametabolic pathway in 7: c w i involved in the critical function ofrepairing oxtdizd macromolecules.PIP1122008-01-02519, PICT 07668& PICT 08 1754