NmEstD is a SFGH. Activity of NmEstD was assayed against SFG (filled circles, ●), SLG (empty circles, ○), and pNPAC (filled triangles, ▼). The results were plotted as a function of substrate concentration and fitted to a rectangular hyperbola. All assays were performed in HEPES buffer (50 mM, pH 7.0) at 37°C using 0.4 μM EstD for SLG and pNPAC or 4 nM EstD for SFG. Units=μmol.min−1. pNPAC, p-nitrophenyl acetate; SFGH, S-formylglutathione hydrolase; SLG, S-lactoylglutathione.