FIG. 4.

Identification of organophosphorous compounds inhibiting AChE by determining the relative inhibition rates for two mutants. The inhibition rate constants of four enzymes (Y71D Y73Q, Y71A, E69W, and E69Y) were estimated for anatoxin-a(s) and for some insecticides. Four inhibition ratios were then tested to obtain a signature for inhibition by anatoxin-a(s) versus inhibition by an insecticide. Y71D Y73Q and Y71A were more rapidly inhibited than E69W and E69Y by anatoxin-a(s) but not by the insecticides tested.