The rate and extent of uptake of the fluorescent probe diS-C3(3) reporting on membrane potential in S. cerevisiae is affected by the strain under study, cell-growth phase, starvation and by the concentration of glucose both in the growth medium and in the monitored cell suspension under non-growth conditions. Killer toxin K1 brings about changes in membrane potential. In all types of cells tested, viz. in glucose-supplied stationary or exponential cells of the killer-sensitive strain S6/1 or a conventional strain RXII, or in glucose-free exponential cells of both strains, both active and heat-inactivated toxin slow down the potential-dependent uptake of diS-C3(3) into the cells. This may reflect "clogging" of pores in the cell wall that hinders, but does not prevent, probe passage to the plasma membrane and its equilibration. The clogging effect of heat-inactivated toxin is stronger than that exerted by active toxin. In susceptible cells, i.e. in exponential-phase glucose-supplied cells of the sensitive strain S6/1, this phase of probe uptake retardation is followed by an irreversible red shift in probe fluorescence maximum lambda max indicating damage to membrane integrity and cell permeabilization. A similar fast red shift in lambda max signifying lethal cell damage was found in heat-killed or nystatin-treated cells.

Institute of Physics Charles University Prague Czech Republic

Zobrazit více v PubMed

Yeast. 1998 Sep 30;14(13):1189-97 PubMed

Folia Microbiol (Praha). 1995;40(2):213-15 PubMed

Int J Biochem Cell Biol. 1999 May;31(5):575-84 PubMed

Yeast. 1993 Nov;9(11):1207-11 PubMed

Folia Microbiol (Praha). 1994;39(6):516-7 PubMed

Biochim Biophys Acta. 1981 May 20;643(3):583-92 PubMed

J Bacteriol. 1974 May;118(2):534-40 PubMed

Folia Microbiol (Praha). 1997;42(3):221-4 PubMed

Microb Drug Resist. 1998 Fall;4(3):143-58 PubMed

J Fluoresc. 1993 Dec;3(4):241-4 PubMed

Biochim Biophys Acta. 1981 May 20;643(3):572-82 PubMed

Folia Microbiol (Praha). 1994;39(6):521-4 PubMed

Arch Microbiol. 1994;162(3):211-4 PubMed

Effect of biocides on S. cerevisiae: relationship between short-term membrane affliction and long-term cell killing

Use of synchronously excited fluorescence to assess the accumulation of membrane potential probes in yeast cells