Ionic channel activity induced by fusion of Rhodospirillum rubrum chromatophores with a planar bilayer lipid membrane.
The present work concerns mechanisms of ionic conductivity of photosynthetic membranes. It is shown that reconstitution of vesicles of photosynthetic membranes (chromatophores) of purple bacteria Rhodospirillum rubrum into a planar bilayer lipid membrane leads to fluctuations of current showing the existence of a channel with a predominant conductance of approximately 230 pS in the presence of 100 mM KCl. Measurements under the conditions of KCl gradient prove that this channel is cation selective (PK/PCl = 7.2). Voltage inactivation of the channel is demonstrated which is prevented by treatment with trypsin.
Antonenko
Y N
YN
A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russian Federation.
Rokitskaya
T I
TI
Kotova
E A
EA
Taisova
A S
AS
D020130:Bacterial Chromatophores / Q000648:ultrastructure*; D002462:Cell Membrane / Q000502:physiology*; D004553:Electric Conductivity; D006863:Hydrogen-Ion Concentration; D007473:Ion Channels / Q000502:physiology*; D008051:Lipid Bilayers; D008561:Membrane Fusion; D010788:Photosynthesis; D011189:Potassium Chloride / Q000494:pharmacology; D012247:Rhodospirillum rubrum / Q000648:ultrastructure*; D014357:Trypsin / Q000494:pharmacology
D007473:Ion Channels; D008051:Lipid Bilayers; D011189:Potassium Chloride; D014357:Trypsin