After aliquots of the purified enzyme (10 μl, 4.35 ng/μl) were separately incubated with 10 μl of buffer, malaoxon (▲ — ▲), paraoxon (○ --- ○), carbaryl (□ – – □), eserine (■ — ■), and BW284C51 (● — ●) at 25°C for 10 min, the mixtures were reacted with ATC-DTNB solution and absorbance changes were monitored by a microplate reader at 405 nm. Residual activities (% of the control of AChE2 and buffer, shown as mean ± SEM (n = 4), are plotted against inhibitor concentrations for IC50 calculation (Section 2.7).