Amplification of the Na+-ATPase of Streptococcus faecalis at alkaline pH

FEBS Lett. 1990 Feb 12;261(1):135-8. doi: 10.1016/0014-5793(90)80654-2.


The Na+-ATPase activity of Streptococcus faecalis was influenced by the medium pH. Activities of the protonophore-resistant Na+ extrusion and the KtrII (active K+ uptake by the Na+-ATPase) were maximal in the cells grown at pH 9.5, and were minimal in those grown at pH 6.0. In the cells grown at pH 7.5, they were moderately observed. The Na+-stimulated ATPase activity of the cells grown at pH 9.5 was about 4-fold higher than that of the cells grown at pH 6.0. Thus, amplification of the Na+-ATPase is remarkable at alkaline pH in this organism, possibly by an increase of the cytoplasmic Na+ level as a signal.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / metabolism*
  • Cation Transport Proteins*
  • Culture Media
  • Enterococcus faecalis / enzymology*
  • Hydrogen-Ion Concentration
  • Kinetics
  • Potassium / metabolism
  • Potassium / pharmacology
  • Sodium / metabolism*
  • Sodium / pharmacology


  • Cation Transport Proteins
  • Culture Media
  • Sodium
  • Adenosine Triphosphatases
  • sodium-translocating ATPase
  • Potassium