Membrane Topology of the α Subunit of Na,K-ATPase

  • M. Mohraz
  • E. Arystarkhova
  • K. J. Sweadner


Although the amino acid sequence of the Na,K-ATPase is known, the transmembrane folding of its a subunit is the subject of considerable controversy. Several lines of evidence (8) support hydropathy plots that predict 4 transmembrane spans in the Nterminal third of the sequence. There is also general agreement that the middle third of the polypeptide chain is entirely cytoplasmic. The confusion lies in the C-terminal third of the sequence where hydropathy plots are ambiguous and models with three, four or six spans have been proposed. Rigorous identification of sites exposed on one side of the membrane or the other is essential for the development of a reliable folding model.


Gold Particle Colloidal Gold Immunoelectron Microscopy Cytoplasmic Side Cyanogen Bromide 
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Copyright information

© Dietrich Steinkopff Verlag GmbH & Co. KG, Darmstadt 1994

Authors and Affiliations

  • M. Mohraz
    • 1
  • E. Arystarkhova
    • 2
  • K. J. Sweadner
    • 2
  1. 1.Dept. of Cell BiologyNew York University School of MedicineNew YorkUSA
  2. 2.Massachusetts General HospitalBostonUSA

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