Ion Permeability of Ciliary Membrane Vesicles Isolated from Tetrahymena. Single-Channel Recording Study on the Membrane Reconstituted into a Planar Lipid Bilayer1

Publisher Website
Google Scholar
Abstract
An ion channel in ciliary membrane vesicles isolated from Tetrahymena pyriformis NT-1 was characterized with a single-channel recording technique applied to the membrane reconstituted into a planar lipid bilayer made of soybean phospholipid. The gating of this channel is independent of membrane potential and it spends most of the time in its open-channel state. It is selective for metal cations over gluconate anion although it little distinguishes cations, Ca2+, Ba2+, Mg2+, and K+. This channel seems to be identical to the monovalent cation channel in Tetrahymena thermophila BIT cilia, which was recently reported by Oosawa and Sokabe {Am. J. Physiol.249, C177–C179, 1985). The channel conductance saturates with increasing ion concentration. The maximum value (in pS) for the single-channel conductance obtained in symmetric solutions of sufficiently high concentration is in the order of K+(212)>Ba2+(41)>Ca2+(22)>Mg2+(20). On the other hand, the affinity of the channel for these ions is in the reverse order.

This publication has 2 references indexed in Scilit: