The role of fluoroacetate-specific dehalogenase and glutathione transferase in the metabolism of fluoroacetamide and 2,4-dinitrofluorobenzene

2,4-Dinitrofluorobenzene (DNFB) reacts with glutathione to form a stable product similar to that formed with the model glutathione-S-transferase (GST) substrate, 1-chloro-2,4-dinitrobenzene (CDNB). DNFB is approx. 40 times als reactive as CDNB in this chemical reaction. The enzymatic defluorination of DNFB also proceeds at a more rapid rate than that of CDNB in the GST assay. Fluoroacetamide (FAM), like fluoroacetate (FAC), undergoes no discernable chemical defluorination. Its enzymatic defluorination is approx. 10% of that observed for FAC and only 0.2% of the rate for DNFB. An antibody raised to the fluoroacetate specific dehalogenase (FSD) precipitated both FAC and FAM defluorinating activity but had no effect on either CDNB or DNFB activity. The data are consistent with the hypothesis that DNFB is metabolized by the GST while FAM is metabolized by the FSD.