Kinetic characterization of affinity purified recombinant HIS-FAAH from Dictyostelium. Initial velocity measurements were made at increasing concentration of arachidonoyl p-nitroaniline (ApNA) and decanoyl p-nitroaniline (DpNA) substrates. Reaction was initiated by addition of 10μg of HIS-FAAH protein purified from Dictyostelium and the reaction was incubated at 37°C for 30 min. Data points are mean ± S.D. values of specific activity from triplicate assays from single batch of enzyme purification and plots were generated by fitting the data points into Michaelis-Menten equation using prism software version 3.0. Inset figures are the structures of ApNA and DpNA. Inset Table 1 details kinetic parameters of HIS-FAAH isolated from Dictyostelium were estimated by fitting the data in Figure 4, to Michaelis-Menten equation.