Lateral Transport of a Lipid Probe and Labeled Proteins on a Cell Membrane

Diffusion coefficients ( D ) of a lipid probe and labeled proteins on L-6 myoblast membranes have been measured giving D (protein) ∼ 2 × 10 -10 square centimeter per second and D (lipid probe) ∼ 9 × 10 -9 square centimeter per second. Some of the membrane proteins are immobile, but the lipid probe diffuses freely over macroscopic distances. Cytochalasin B slows protein but not lipid probe diffusion.