Figure 7.
Coated vesicles have stoichiometric levels of COP and GAP, and significantly reduced levels of ARF1. For A, the two-stage incubation was scaled up fivefold with the supernatant derived from the second stage and then loaded at the bottom of a continuous sucrose gradient for equilibrium centrifugation followed by fractionation and immunoblotting with antibodies indicated. Quantitation of β-COP, ARF1, and GAP was performed based on immunoblotting using known amounts of purified proteins, as indicated in B.