Figure 5.

Characterization of FplA inhibitors. A, IC₅₀ assays showing varying degrees of inhibition toward FplA by inhibitors previously shown to inhibit a variety of lipases. B, structure and names of tested inhibitors. C, IC₅₀ plot of MAFP, the most potent (11 nm) FplA inhibitor characterized. D, analysis of the active site of FplA shows that the active site serine (Ser-98) reacts with ActivX TAMRA-FP probe but does not bind in the presence of the competitive inhibitor MAFP. S98A and D243A mutants will not bind the serine active site probe. Western blotting (IB) and SDS-polyacrylamide gels stained with Coomassie Blue serve as load controls for all constructs.