Molecular size-dependent leakage of intracellular molecules from frog skeletal muscle fibers permeabilized with beta-escin.
The permeability of beta-escin-treated cell membrane was characterized in terms of the permeant molecular size, by monitoring the leak of cytoplasmic molecules in frog skeletal muscle fibers. With a low concentration of beta-escin (5 microM), most of the cellular ATP was lost within 30-40 min (as revealed by rigor force generation), whereas a fluorescence-labeled dextran injected into the cytoplasm (approximately 10 kDa) and cytoplasmic proteins (14-80 kDa) slowly leaked out of the cell. A high concentration of beta-escin (50-100 microM) accelerated the leak of large molecules. Therefore, low concentrations of beta-escin may be used as a means of permeabilizing the cell membrane to relatively small molecules, while retaining a major fraction of the cellular macromolecules.
Konishi
M
M
Department of Physiology, Jikei University School of Medicine, Tokyo, Japan.
Watanabe
M
M
D000255:Adenosine Triphosphate; D000818:Animals; D002462:Cell Membrane; D004928:Escin / Q000494:pharmacology*; D005453:Fluorescence; D018482:Muscle, Skeletal; D011506:Proteins / Q000378:metabolism*; D011896:Rana temporaria; D013997:Time Factors
D011506:Proteins; D004928:Escin; D000255:Adenosine Triphosphate