FIGURE 4.

Results of inhibition study of ADAM17 with AHA (A) and compound 15 (B) in the presence of various substrates. Inhibition of ADAM17-mediated hydrolysis of glycosylated (substrate 1), nonglycosylated (substrate 4), and α-helical (substrate 9) substrates was measured using 10-point 1:3-fold dilutions of AHA and compound 15. The data were analyzed using GraphPad Prism. The noncompetitive exosite inhibitor (compound 15) preferentially abrogated hydrolysis of the glycosylated substrate and spared hydrolysis of nonglycosylated and α-helical substrates, suggesting that α-helical and glycosylated substrates bind to ADAM17 in a different fashion and that the α-helical substrate binding does not interact with a pocket where compound 15 can be localized.