2Institute of Cell Biophysics, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia; E-mail: email@example.com
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Received January 14, 2008; Revision received May 23, 2008
Silver ions induce the efflux of potassium from cells of the yeast Saccharomyces cerevisiae but have no such effect on spheroplasts. Copper ions and the natural fungicide 2-O-3-hydroxyhexanoyl-beta-D-glucopyranosyl-(1→4)-(6-O-acetyl-beta-D-glucopyranosyl-(1→16)-2,15,16-trihydroxyhexadecanoic acid) induce the efflux of potassium ions from both cells and spheroplasts of S. cerevisiae. Silver and copper ions inhibit the activity of the plasma membrane H+-ATPase during the treatment of both cells and spheroplasts. It is supposed that the inability of silver ions to stimulate potassium efflux from spheroplasts results from damage to some components of K+ transport systems during preparation of spheroplasts.
KEY WORDS: potassium, silver, copper, cell wall, plasma membrane, H+-ATPase, ion leakage, yeast Saccharomyces cerevisiae