In a recent article published in PNAS, Prof. Emile Van Schaftingen (WEBLIO investigator at Université Catholique de Louvain (UCL)), Alessio Perracchi and Maria Veiga-da-Cunha show that the protein named ‘nitrilase-like protein 1” (Nit1) encoded by a vast majority of eukaryotes and the corresponding yeast protein efficiently hydrolyze the deaminated form of the major intracellular antioxidant glutathione.
They also show that deaminated glutathione is produced by a side-activity of numerous transaminases. Thus, Nit1 metabolizes an undesired product arising from the slow and erroneous transformation of an important metabolite by several abundant intracellular enzymes. The importance of this Nit1 function is underscored by the finding that enzymes with the same activity occur in Escherichia coli and in numerous glutathione-producing bacteria. The physiological role of this new repair enzyme is presumably to allow organisms to recover cysteine, a precious, sulfur-containing amino acid.
Overall this work further stresses the importance of metabolite repair, several examples of which have been discovered by the group of E. Van Schaftingen.
Référence : Perracchi A et al. Nit1 is a metabolite repair enzyme that hydrolyzes deaminated glutathione. PNAS (2017) Doi: 10.1073/pnas.1613736114