Figure 5.

The monoclonal antibodies aZ-mAb-6 and -7 specifically inhibit human matriptase. The ability of aZ-mAb-4, -6, and -7 to inhibit human matriptase and other closely related serine proteases was tested in an activity assay. For all assays, an excess of antibody (400 nm) was preincubated with the proteases for 1 h at 37 °C before the addition of substrate. Human matriptase, acSPD (100 pm), was almost completely inhibited by aZ-mAb-6 (green line) and aZ-mAb-7 (black line), but not by aZ-mAb-4 (red line). The activity of mouse matriptase SPD (100 pm), human uPA (1 nm), hepsin (1 nm), and HGFA (5 nm) were not significantly inhibited by any of the monoclonal antibodies. The graphs shown are representative of three replicates.