An ouabain-sensitive Na+,K+-ATPase in tentacles of the sea anemone Stichodactyla helianthus

Susan Corey Specht*, Roberto Lopez-Rosado, Cynthia Santos-Berrios, Rosa Figueroa-Nieves

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


Tentacles of Stichodactyla helianthus contain an ouabain-inhibitable, (Na+,K+)-stimulated ATPase. The K0.5 for Na+ was 24 mM and for K+, 3.2 mM. The apparent affinity for ouabain was low, I50 = 10-4 M. The order of cation affinities was Rb+ > K+ > NH4+ = Cs+. The catalytic subunit of the enzyme comprised a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Mr = 105 kDa, that was phosphorylated by [32P]ATP in the presence of NaCl and dephosphorylated by the addition of KCl. The α subunit was weakly reactive with antibodies directed against the rat α subunit.

Original languageEnglish (US)
Pages (from-to)555-563
Number of pages9
JournalComparative Biochemistry and Physiology -- Part B: Biochemistry and
Issue number3
StatePublished - Mar 1995


  • (Na+K)-ATPase
  • Ancestral form
  • Cnidarian
  • Coelenterate
  • Na pump
  • Na,K-ATPase, Na/K-ATPase
  • Ouabain
  • Tentacles

ASJC Scopus subject areas

  • Biochemistry
  • Physiology
  • Molecular Biology


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