These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Mg/KCl-ATPase of plant plasma membranes is an electrogenic pump.
    Author: Sze H, Churchill KA.
    Journal: Proc Natl Acad Sci U S A; 1981 Sep; 78(9):5578-82. PubMed ID: 16593089.
    Abstract:
    The function of the Mg(2+)-requiring KCl-stimulated ATPase (ATP phosphohydrolase, EC 3.6.1.3) of higher plants in active ion transport was investigated by using a purified microsomal fraction containing sealed plasma membrane vesicles. (Sze, H. (1980) Proc. Natl. Acad. Sci. USA 77, 5904-5908). A transmembrane electrical potential (+30 to +44 mV), monitored by uptake of a permeant anion ((35)SCN(-)), was generated specifically by ATP in purified microsomal vesicles of tobacco callus. ATP-dependent (35)SCN(-) uptake required Mg(2+), was optimal at pH 6.75, and showed similar ATP concentration dependence as the Mg(2+)-requiring KCl-stimulated ATPase activity. Plasma membrane ATPase inhibitors (N,N'-dicyclohexylcarbodiimide and vanadate) inhibited generation of the ATP-dependent electrical potential. A proton conductor (carbonyl cyanide m-chlorophenylhydrazone), but not a K(+) ionophore (valinomycin), completely collapsed the electrical potential. The results provide in vitro evidence that the Mg(2+)/KCl-ATPase of higher plants is an electrogenic pump. These results are consistent with the hypothesis that an electrogenic H(+) pump is catalyzed by the plasma membrane ATPase of plants.
    [Abstract] [Full Text] [Related] [New Search]