Spatial distribution and activity of Na +/K +-ATPase in lipid bilayer membranes with phase boundaries

Research output: Contribution to journalJournal articleResearchpeer-review

  • Tripta Bhatia
  • Flemming Cornelius
  • Jonathan Brewer
  • Luis A. Bagatolli
  • Adam C. Simonsen
  • John H. Ipsen
  • Mouritsen, Ole G.

We have reconstituted functional Na +/K +-ATPase (NKA) into giant unilamellar vesicles (GUVs) of well-defined binary and ternary lipid composition including cholesterol. The activity of the membrane system can be turned on and off by ATP. The hydrolytic activity of NKA is found to depend on membrane phase, and the water relaxation in the membrane on the presence of NKA. By collapsing and fixating the GUVs onto a solid support and using high-resolution atomic-force microscopy (AFM) imaging we determine the protein orientation and spatial distribution at the single-molecule level and find that NKA is preferentially located at l o/l d interfaces in two-phase GUVs and homogeneously distributed in single-phase GUVs. When turned active, the membrane is found to unbind from the support suggesting that the protein function leads to softening of the membrane.

Original languageEnglish
JournalBiochimica et Biophysica Acta - Biomembranes
Volume1858
Issue number6
Pages (from-to)1390-1399
Number of pages10
ISSN0005-2736
DOIs
Publication statusPublished - 1 Jun 2016

    Research areas

  • Domains, Giant unilamellar vesicles, Membrane biophysics, Membrane protein, Membranes, Na /K -ATPase, Protein-lipid interaction

ID: 230974172