Catalyzes the hydrolysis of the amide bond in N-(4-oxoglutarate)-L-cysteinylglycine (deaminated glutathione), a metabolite repair reaction to dispose of the harmful deaminated glutathione. Plays a role in cell growth and apoptosis: loss of expression promotes cell growth, resistance to DNA damage stress and increased incidence to NMBA-induced tumors. Has tumor suppressor properties that enhances the apoptotic responsiveness in cancer cells; this effect is additive to the tumor suppressor activity of FHIT. It is also a negative regulator of primary T-cells. H2O + N-(4-oxoglutaryl)-L-cysteinylglycine = 2-oxoglutarate + L-cysteinylglycine According to Rosetta Stone theory, the existence of a fusion protein in one genome predicts that the separate polypeptides expressed in other organisms function in the same cellular or biochemical pathway. In Drosophila melanogaster and Caenorhabditis elegans, NitFhit is a fusion protein composed of a C-terminal Fhit domain and a domain related to plant and bacterial nitrilase. Belongs to the carbon-nitrogen hydrolase superfamily. NIT1/NIT2 family.