A class of mild surfactants that keep integral membrane proteins water-soluble for functional studies and crystallization

Mol Membr Biol. 2011 Apr;28(3):171-81. doi: 10.3109/09687688.2011.552440. Epub 2011 Feb 14.


Mixed protein-surfactant micelles are used for in vitro studies and 3D crystallization when solutions of pure, monodisperse integral membrane proteins are required. However, many membrane proteins undergo inactivation when transferred from the biomembrane into micelles of conventional surfactants with alkyl chains as hydrophobic moieties. Here we describe the development of surfactants with rigid, saturated or aromatic hydrocarbon groups as hydrophobic parts. Their stabilizing properties are demonstrated with three different integral membrane proteins. The temperature at which 50% of the binding sites for specific ligands are lost is used as a measure of stability and dodecyl-β-D-maltoside ('C12-b-M') as a reference for conventional surfactants. One surfactant increased the stability of two different G protein-coupled receptors and the human Patched protein receptor by approximately 10°C compared to C12-b-M. Another surfactant yielded the highest stabilization of the human Patched protein receptor compared to C12-b-M (13°C) but was inferior for the G protein-coupled receptors. In addition, one of the surfactants was successfully used to stabilize and crystallize the cytochrome b(6 )f complex from Chlamydomonas reinhardtii. The structure was solved to the same resolution as previously reported in C12-b-M.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chlamydomonas reinhardtii / chemistry
  • Crystallization / methods*
  • Cytochrome b6f Complex / chemistry
  • Glucosides / chemistry
  • Humans
  • Membrane Proteins / chemistry*
  • Patched Receptors
  • Receptors, Cell Surface / chemistry
  • Receptors, G-Protein-Coupled / chemistry
  • Solubility
  • Surface-Active Agents / chemistry*
  • Water / chemistry*


  • Glucosides
  • Membrane Proteins
  • Patched Receptors
  • Receptors, Cell Surface
  • Receptors, G-Protein-Coupled
  • Surface-Active Agents
  • Water
  • dodecyl maltoside
  • Cytochrome b6f Complex