Anti–SNAP-23 antibody inhibits lysosome secretion.

Panel A: SLO-permeabilized platelets were incubated with increasing amounts of a polyclonal antibody against SNAP-23 (ab23, 0-38 μg/mL). The release of hexosaminidase was measured as before and normalized to the control (no addition of ab23). Panel B: SLO-permeabilized platelets were incubated on ice for 30 minutes with buffer (control), 20 μg/mL with ab23, with 20 μg/mL that had been preincubated with 0.5 mg/mL recombinant SNAP-23, with 0.5 mg/mL recombinant SNAP-23 alone, and with 0.15 mg/mL C-terminal peptide of SNAP-23. Platelets were activated with 10 μmol/L Ca⁺⁺ and the release of hexosaminidase was measured and normalized to the control group.