Fig. 10. Measurement of the interaction forces between the R-SNARE-like motif of tomosyn-1 and the Q-SNAREs syntaxin-1 and SNAP-25. A GST-fusion protein containing the SNARE-like motif of tomosyn-1 was fixed to the cantilever of the AFM. Syntaxin-1 (left panel) or the syntaxin-1-SNAP25 complex (right panel) were attached on the mica. The histograms show the frequencies of the forces of the specific events (gray bars). White bars indicate the frequencies and forces of nonspecific events measured using GST-covered mica. The mean unbinding forces were 152±9 and 237±13 pN for the interactions with syntaxin-1 and with the syntaxin-1-SNAP25 complex, respectively.