ISSN:
1432-1424
Keywords:
Ca2+-activated K+ channels
;
rabbit colon
;
basolateral membranes
;
Ba2+
;
quinine
;
scorpion venom
;
trifluoperazine
;
lipid bilayers
;
reconstitution
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Summary A highly enriched preparation of basolateral membrane vesicles was isolated from rabbit distal colon surface epithelial cells employing the method described by Wiener, Turnheim and van Os (Weiner, H., Turnheim, K., van Os, C.H. (1989)J. Membrane Biol.110:147–162) and incorporated into planar lipid bilayers. With very few exceptions, the channel activity observed was that of a high conductance, Ca2+-activated K+ channel. This channel is highly selective for K+ over Na+ and Cl−, displays voltage-gating similar to “maxi” K(Ca) channels found in other cell membranes, and kinetic analyses are consistent with the notion that K+ diffusion through the channel involves either the binding of a single K+ ion to a site within the channel or “single-filling” (“multi-ion occupancy”). Channel activity is inhibited by the venom from the scorpionLeiurus quinquestriatus, Ba2+, quinine, and trifluoperazine. The possible role of this channel in the function of these cells is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01870955
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