Stoichiometry of lipid-protein interaction assessed by hydrophobic photolabeling

FEBS Lett. 2006 Jan 23;580(2):607-12. doi: 10.1016/j.febslet.2005.12.078. Epub 2006 Jan 3.

Abstract

Here we undertook a comparative study of the composition of the lipid annulus of three ATPases pertaining to the P-type family: plasma membrane calcium pump (PMCA), sarcoplasmic reticulum calcium pump (SERCA) and Na,K-ATPase. The photoactivatable phosphatidylcholine analogue [(125)I]TID-PC/16 was incorporated into mixtures of dimyristoyl phosphatidylcholine (DMPC) and each enzyme with the aid of the nonionic detergent C(12)E(10). After photolysis, the extent of the labeling reaction was assessed to determine the lipid:protein stoichiometry: 17 for PMCA, 18 for SERCA, 24 for the Na,K-ATPase (alpha-subunit) and 5.6 mol PC/mol protein for the Na,K-ATPase (beta-subunit).

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium-Transporting ATPases / metabolism*
  • Cation Transport Proteins / metabolism*
  • Detergents / chemistry
  • Humans
  • Light
  • Lipids / chemistry*
  • Molecular Structure
  • Phosphatidylcholines / metabolism
  • Plasma Membrane Calcium-Transporting ATPases
  • Rabbits
  • Sarcoplasmic Reticulum Calcium-Transporting ATPases
  • Sodium-Potassium-Exchanging ATPase / metabolism*
  • Staining and Labeling / methods
  • Swine

Substances

  • Cation Transport Proteins
  • Detergents
  • Lipids
  • Phosphatidylcholines
  • Plasma Membrane Calcium-Transporting ATPases
  • Sarcoplasmic Reticulum Calcium-Transporting ATPases
  • Calcium-Transporting ATPases
  • Sodium-Potassium-Exchanging ATPase