NSF-2 peptide inhibited -granule secretion in permeabilized human platelets. Platelets were preincubated with saponin and NSF-2 or scr-NSF-2 peptides or with no peptide. Granule secretion was induced by increasing free Ca²⁺-concentration to 10 μmol/L. -Granule secretion was monitored by ELISA measuring β-thromboglobulin in the cell supernatants (see Materials and Methods; mean ± SD, n = 2).