Diameter of the mammalian porin channel in open and "closed" states: direct measurement at the single channel level in planar lipid bilayer.
Porin isolated from bovine skeletal muscle was reconstitute in planar lipid bilayers under voltage clamp conditions. A set of non-electrolytes were used as molecular probes for determining the pore diameter. The maximal diameter of the open channel was estimated to be 3.02 +/- 0.26 nm. As observed for other porin channels, a large transmembrane potential drove the channel into a "closed" state. The channel transition to the low conductance (closed) state was followed by a decrease in the maximal diameter of the channel to 2.4 +/- 0.08 nm.
Krasilnikov
O V
OV
Laboratory of Molecular Physiology, Institute of Physiology and Biophysics, Tashkent, Uzbekistan. kras@npd.ufpe.br
Carneiro
C M
CM
Yuldasheva
L N
LN
Campos-de-Carvalho
A C
AC
Nogueira
R A
RA
D000818:Animals; D066298:In Vitro Techniques; D007473:Ion Channels / Q000502:physiology*; D008051:Lipid Bilayers; D008322:Mammals; D010316:Particle Size; D018408:Patch-Clamp Techniques; D018272:Porins / Q000648:ultrastructure*
D007473:Ion Channels; D008051:Lipid Bilayers; D018272:Porins