Sizing the pore of the volume-sensitive anion channel by differential polymer partitioning.
Partitioning of ethylene glycol and its polymeric forms into the pore of the volume-sensitive outwardly rectifying (VSOR) anion channel was studied to assess the pore size. Polyethylene glycol (PEG) PEG 200-300 (Rh = 0.27-0.53 nm) effectively suppressed the single-channel currents, whereas PEG 400-4000 (Rh = 0.62-1.91 nm) had little or no effect. Since all the molecules tested effectively decreased electric conductivity of the bulk solution, the observed differential effects between PEG 200-300 and PEG 400-4000 on the VSOR single-channel current are due to their limited partitioning into the channel lumen. The cut-off radius of the VSOR channel pore was assessed to be 0.63 nm.
Ternovsky
Vadim I
VI
Department of Cell Physiology, National Institute for Physiological Sciences, Okazaki 444-8585, Japan.
Okada
Yasunobu
Y
Sabirov
Ravshan Z
RZ
D000838:Anions; D002460:Cell Line; D004847:Epithelial Cells / Q000166:cytology / Q000502:physiology; D006801:Humans; D007473:Ion Channels / Q000502:physiology* / Q000648:ultrastructure*; D008564:Membrane Potentials / Q000502:physiology; D018408:Patch-Clamp Techniques; D011092:Polyethylene Glycols
D000838:Anions; D007473:Ion Channels; D011092:Polyethylene Glycols