Analyzing membrane surface activity of NΔ17-Arf1. Lipids of a Golgi-like lipid composition containing 5 mol% Ni++ lipids were spotted on a glass surface in a chamber as described in Materials and methods and hydrated with buffer. Thereafter, NΔ17-Arf1 was injected to the rehydrated membrane sheets. No tubulation is observed at concentrations ranging from 1 to 5 µM. Time-lapse images were recorded using a phase-contrast microscope (Axiomat 200M) at one frame per second using a Plan Apochromat 100× objective (NA = 1.4). Images were captured with a camera (AxioCam MRm), and the imaging software used was Axiovision and ImageJ.
