FIGURE 4.

Dissociation rates of cargo from Unc119a/b in the presence and absence of Arl proteins. The dissociation rates of cargo release in the presence and absence of Arl proteins were measured by a stopped flow instrument in the fluorescence polarization mode at 25 °C in buffer A. 1 μm preformed complex of Unc119a (A) or Unc119b (B) with fluorescein-labeled N-terminal myristoylated GNAT1 peptide was mixed with a 100-fold excess of unlabeled N-terminal myristoylated GNAT1 peptide in the presence or absence of a 10-fold excess of Arl2/3·GppNHp proteins as indicated. The kinetics of dissociation was monitored, and dissociation rate constants were calculated using first order rate equations. All bar graphs show the average of 5–7 measurements.