[Δ17]Arf1-Mg2+-GDP binding to Arno and Arno4M in the presence of BFA and GDP. Kinetics of [Δ17]Arf1-Mg2+-GDP binding to immobilized Arno (383 RU) (A) and Arno4M (355 RU) (B) in the presence of 2 μm GDP and 100 μm BFA during the association time. Increasing concentrations of Arf1 were injected (25, 50, 100, 200, 400, 800 and 1600 nm; from bottom to top).