Functional characterization of methionine sulfoxide reductases from Leptospira interrogans

• Published in: Biochimica et biophysica acta. Proteins and proteomics 2021-02, Vol.1869 (2), p.140575, Article 140575
• Main Authors: Sasoni, Natalia, Hartman, Matías D., Guerrero, Sergio A., Iglesias, Alberto A., Arias, Diego G.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence - genetics; Catalysis; Cytoplasm - chemistry; Cytoplasm - enzymology; Genome, Bacterial - genetics; Glutaredoxin; Humans; Leptospira; Leptospira interrogans - enzymology; Leptospira interrogans - genetics; Methionine - chemistry; Methionine - genetics; Methionine - metabolism; Methionine sulfoxide reductase; Methionine Sulfoxide Reductases - chemistry; Methionine Sulfoxide Reductases - genetics; Methionine Sulfoxide Reductases - ultrastructure; Oxidation-Reduction; Redox metabolism; Sequence Homology, Amino Acid; Stereoisomerism; Substrate Specificity; Thioredoxin
• ISSN: 1570-9639; 1878-1454
• DOI: 10.1016/j.bbapap.2020.140575

Methionine (Met) oxidation leads to a racemic mixture of R and S forms of methionine sulfoxide (MetSO). Methionine sulfoxide reductases (Msr) are enzymes that can reduce specifically each isomer of MetSO, both free and protein-bound. The Met oxidation could change the structure and function of many proteins, not only of those redox-related but also of others involved in different metabolic pathways. Until now, there is no information about the presence or function of Msrs enzymes in Leptospira interrogans. We identified genes coding for putative MsrAs (A1 and A2) and MsrB in L. interrogans serovar Copenhageni strain Fiocruz L1-130 genome project. From these, we obtained the recombinant proteins and performed their functional characterization. The recombinant L. interrogans MsrB catalyzed the reduction of Met(R)SO using glutaredoxin and thioredoxin as reducing substrates and behaves like a 1-Cys Msr (without resolutive Cys residue). It was able to partially revert the in vitro HClO-dependent inactivation of L. interrogans catalase. Both recombinant MsrAs reduced Met(S)SO, being the recycle mediated by the thioredoxin system. LinMsrAs were more efficient than LinMsrB for free and protein-bound MetSO reduction. Besides, LinMsrAs are enzymes involving a Cys triad in their catalytic mechanism. LinMsrs showed a dual localization, both in cytoplasm and periplasm. This article brings new knowledge about redox metabolism in L. interrogans. Our results support the occurrence of a metabolic pathway involved in the critical function of repairing oxidized macromolecules in this pathogen. [Display omitted] •LinMsrB catalyzed the reduction of Met(R)SO using Grx or Trx as substrates.•LinMsrAs reduced Met(S)SO using the homologous Trx system.•LinMsrAs present a vicinal resolutive Cys residue in their active sites.•LinMsrB was able to revert the in vitro HClO-dependent inactivation of catalase.•LinMsrs show cytoplasmic and periplasmic localization in L. interrogans.