Disulfide reduction is a central aspect of life. In fact, the production of deoxyribonucleotides, components of DNA, involves thiol-disulfide exchange reactions. The thioredoxin system is composed of two proteins (Thioredoxin (Trx), and Thioredoxin Reductase (TrxR)), and NADPH and plays a central role in desoxyribunucleotides synthesis, besides acting as a reductant of antioxidant proteins such as Peroxiredoxins and Methionine Sulfoxide Reductase, among other systems. Our research group, characterized cytosolic thioredoxin system from Saccharomyces cerevisiae, showing ScTrxR1 is able to reduce yeast Trxs with high efficiency (kcat / KM ~ 10^7 M^-1 s^-1), but did not observe reaction in significant rates with Trxs from Escherichia coli and Homo Sapiens (Oliveira et .al., 2010). In this research project, we intend to advance these studies, characterizing the mitochondrial thioredoxin system from Saccharomyces cerevisiae (composed of ScTrxR2 ScTrx3 + NADPH +) and also the thioredoxin system from Aspergillus fumigatus (composed of AfTrxR1 AfTrx1-4 + NADPH +), aiming to characterize specificities of TrxRs towards Trx from various organisms using enzymatic assays and structural approaches.
News published in Agência FAPESP Newsletter about the scholarship: