Glutathione (GSH) reduces the open probability of mechanosensitive channels in Escherichia coli protoplasts.

The effects of glutathione (reduced GSH, and oxidized GSSG) on mechanosensitive (MS) ion channels from Escherichia coli protoplasts were investigated using excised, inside-out membrane patches. Our studies demonstrate here that 5 mM GSH irreversibly reduces the activities of the 560-pS MS channel by approximately 70-75% whereas 5 mM GSSG did not alter the MS channel currents. In addition, millimolar concentrations of dithiothreitol had similar although weaker effects to GSH. The physiological concentration of GSH in E. coli cytoplasm ranges from 3.5 mM to 6.6 mM, which may indicate that under normal conditions these MS channels open less due to membrane stretch.