Fig. 2. Diffusion coefficients, D_cyt, of globular proteins spanning a range of molecular mass (redrawn and modified from Arrio-Dupont et al., 2000). Included are data obtained using cultured myotubes microinjected with fluorescently labeled proteins (Arrio-Dupont et al., 2000) (filled circles) and data obtained by measurement of the rates of diffusion of enzymes out of skinned, adult fibers (open circles) (Maughan and Lord, 1988).