A patch-clamp investigation of the Streptococcus faecalis cell membrane.
The patch-clamp technique was used to study the membrane of giant protoplasts from the gram-positive bacterium Streptococcus faecalis, demonstrating the presence of ion-conducting pores in the cytoplasmic membrane of procaryotes. The single channel recordings were characterized by a variety of conductances, ranging up to a few nanoSiemens, arising from stretch-activated, voltage-modulated, cooperative channels. Activation by stretch and voltage took place via both a decrease of the mean closed time and an increase of the mean open time of the channels, which are strictly controlled in intact cells, where they might constitute parts of a membrane apparatus or transport system.
Szabó
I
I
CNR Unit, Department of Biomedical Sciences, Padova, Italy.
Petronilli
V
V
Zoratti
M
M
D002462:Cell Membrane / Q000502:physiology / Q000648:ultrastructure; D002478:Cells, Cultured; D004594:Electrophysiology / Q000379:methods*; D013293:Enterococcus faecalis / Q000502:physiology / Q000648:ultrastructure*; D007473:Ion Channels / Q000502:physiology / Q000648:ultrastructure; D008564:Membrane Potentials / Q000502:physiology
D007473:Ion Channels