The effect of bilayer thickness on the activity of (Na+ + K+)-ATPase

Biochim Biophys Acta. 1981 Mar 6;641(2):416-21. doi: 10.1016/0005-2736(81)90498-3.


The activities of purified (Na+ + K+)-ATPase supported by a series of phosphatidylcholines with monounsaturated (cis-9) fatty acyl chains (di(n : 1) phosphatidylcholine) varying in length from n = 12 to n = 23 were determined by the lipid titration technique. The ATPase activity at 20 degrees C decreased from 2.9 to 0.1 mumol/min per mg protein as n was decreased from 16 to 12 and decreased from 2.9 to 1.0 mumol/min per mg protein as n was increased from 20 to 23. In further experiments, the di(n : 1) phosphatidylcholine-ATPase complexes were treated with increasing proportions of n-decane, which has been shown previously to increase the thickness of black lipid membranes. n-Decane caused a large increase (greater than 20-fold) in activity of the short-chain complexes (n = 12,13); for n = 14--18, the ATPase activity first increased and subsequently decreased as the proportion of decane was increased, and for n = 20 or 23 decane caused a progressive decrease in activity with increasing concentration. These effects confirm qualitatively that a major factor determining the activity in each bilayer is its thickness. This behaviour closely parallels that of the (Ca2+ + Mg2+)-ATPase of sarcoplasmic reticulum [1] and suggests that a major class of trans-membrane transport proteins may have a similar dependence on bilayer thickness.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkanes / metabolism
  • Alkanes / pharmacology
  • Animals
  • Ca(2+) Mg(2+)-ATPase
  • Calcium-Transporting ATPases / metabolism
  • Kidney / enzymology*
  • Lipid Bilayers / metabolism*
  • Phosphatidylcholines / metabolism
  • Sodium-Potassium-Exchanging ATPase / metabolism*
  • Swine


  • Alkanes
  • Lipid Bilayers
  • Phosphatidylcholines
  • Ca(2+) Mg(2+)-ATPase
  • Calcium-Transporting ATPases
  • Sodium-Potassium-Exchanging ATPase
  • decane