The concentration dependence of the depolarization of yeast by monovalent cations.
Monovalent cations decrease the initial rate of uptake of the membrane potential probe 2-(dimethylaminostyryl)-1-ethyl-pyridinium (DMP) into metabolizing cells, showing that the cells are depolarized. A steep decrease in this rate was found even at low cation concentrations, reaching 62%, 42%, 58%, 40% and 40% at high concentrations of K+, Rb+, Cs+, Na+ and Li+, respectively. The corresponding concentrations at which half-maximum decrease was found were 0.22, 0.36, 1.2, 17 and 17 mM. These values are of the same order of magnitude as the half-saturation concentrations for monovalent cation uptake by the yeast.
Borst-Pauwels
G W
GW
Laboratory of Cell Biology, Catholic University, Faculty of Science, Nijmegen, Netherlands.
van de Mortel
J B
JB
Theuvenet
A P
AP
D002414:Cations, Monovalent / Q000494:pharmacology*; D005456:Fluorescent Dyes / Q000032:analysis; D008564:Membrane Potentials / Q000502:physiology*; D011726:Pyridinium Compounds / Q000032:analysis; D012441:Saccharomyces cerevisiae
D002414:Cations, Monovalent; D005456:Fluorescent Dyes; D011726:Pyridinium Compounds; C025042:2-(dimethylaminostyryl)-1-ethylpyridinium