Xl. Zhou et al., FUNCTIONAL RECONSTITUTION OF ION CHANNELS FROM PARAMECIUM CORTEX INTOARTIFICIAL LIPOSOMES, The Journal of membrane biology, 144(3), 1995, pp. 199-208
Toward isolating channel proteins from Paramecium, we have explored th
e possibility of functionally reconstituting ion channels in an artifi
cial system. Proteins from Paramecium cortex reconstituted with soybea
n azolectin retained several channels whose activities were readily re
gistered under patch clamp. The most commonly encountered activities w
ere three: (i) a 71-pS cation channel that opens at all voltages unles
s di-or trivalent cations were added to close them, (ii) a 40 pS monov
alent cation channel, and (iii) a large-conductance channel that prefe
rs anions and exhibits many subconductance states. These channels surv
ived mild detergent treatments without observable functional alteratio
ns. The possible origin of these channels from internal membranes, the
possible role of 71-pS channel in internal Ca2+ release, and the pros
pects of their purification are discussed.