PMID: 10009Oct 13, 1976

Effect of ionophores A23187 and nigericin on the light-induced redistribution of Mg2+, K+ and H+ across the thylakoid membrane

Biochimica Et Biophysica Acta
A A Bulychev, W J Vredenberg

Abstract

Passive redistributions of Mg2+ and K+ ions across the thylakoid membranes, occurring in association with the light-driven electrogenic influx of hydrogen ions have been examined in suspensions of broken spinach chloroplasts under a variety of conditions. (i) In accord with results of Hind el al. (Proc. Natl. Acad. Sci. U.S. (1974) 71, 1484), it was found that at a low K/Mg concentration ratio in the medium, the K-efflux is negligibly small, whereas a substantial Mg-efflux is observed. The converse is true when the K/Mg concentration ratio in the medium is high. (ii) In the presence of A23187, which was found to cause approximately a 60% inhibition of the light-induced pH-gradient, a significant influx of Mg2+ was observed in the light at a high K/Mg concentration ratio. Conversely the Mg-influx was small in the presence of A23187 when the K/Mg concentration ratio in the medium was low. Under these conditions, the Mg-influx was considerably increased upon the addition of valinomycin. A23187 was found not to affect the K-efflux in the light. (iii) The light-induced K-influx observed in the presence of nigericin also was found to be dependent on the concentration ratio of the monovalent and divalent cation. Its magnitude increase...Continue Reading

References

Apr 1, 1974·Proceedings of the National Academy of Sciences of the United States of America·G HindS Izawa
Jan 1, 1970·Annual Review of Biochemistry·D A Walker, A R. Crofts
Nov 1, 1969·Archives of Biochemistry and Biophysics·E L GrossA San Pietro
Jan 14, 1969·Biochimica Et Biophysica Acta·P S Nobel
Apr 8, 1969·Biochimica Et Biophysica Acta·D W Deamer, L Packer
Aug 1, 1965·Archives of Biochemistry and Biophysics·R A Dilley, L P Vernon
Sep 30, 1961·Biochimica Et Biophysica Acta·J BRUINSMA

Citations

Jul 1, 1980·Archives of Biochemistry and Biophysics·G Ben-Hayyim, G H Krause
May 6, 2008·Biochimica Et Biophysica Acta·Pierre Joliot, Anne Joliot
Feb 1, 1978·European Journal of Biochemistry·G Ben-Hayyim

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