Localization of Na+-K+ ATPases in quasi-native cell membranes

Nano Lett. 2009 Dec;9(12):4489-93. doi: 10.1021/nl902803m.

Abstract

Na(+)-K(+) ATPases have been observed and located by in situ AFM and single molecule recognition technique, topography and recognition imaging (TREC) that is a unique technique to specifically identify single protein in complex during AFM imaging. Na(+)-K(+) ATPases were well distributed in the inner leaflet of cell membranes with about 10% aggregations in total recognized proteins. The height of Na(+)-K(+) ATPases measured by AFM is in the range of 12-14 nm, which is very consistent with the cryoelectron microscopy result. The unbinding force between Na(+)-K(+) ATPases in the membrane and anti-ATPases on the AFM tip is about 80 pN with the apparent loading rate at 40 nN/s. Our results show the first visualization of an essential membrane protein, Na(+)-K(+) ATPase, in quasi-native cell membranes and may be significant to reveal the interactions between Na(+)-K(+) ATPases and other membrane proteins at the molecular level.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomimetic Materials / chemistry*
  • Materials Testing / methods
  • Membranes, Artificial*
  • Microscopy, Atomic Force / methods*
  • Molecular Probe Techniques*
  • Sodium-Potassium-Exchanging ATPase / analysis*
  • Sodium-Potassium-Exchanging ATPase / chemistry*
  • Sodium-Potassium-Exchanging ATPase / ultrastructure

Substances

  • Membranes, Artificial
  • Sodium-Potassium-Exchanging ATPase