Figure 2.

Native as well as recombinant tagmin binds SNAP-25 in a saturable and stoichiometric manner. Native tagmin immunopurified from brain cortex (A) and the recombinant cytoplasmic domain of tagmin (B) were incubated with increasing amounts of His₆–SNAP-25 in the presence or absence of 200 μM free calcium as indicated. As control, beads containing the anti-tagmin antibody used for immunoprecipitation (15) (A, Control Ab) or GST (B, GST Control) were incubated with the maximal amount of His₆–SNAP-25 (32 μg) in the presence or absence of calcium.