Membrane biology visualized in nanometer-sized discs formed by styrene maleic acid polymers

Biochim Biophys Acta Biomembr. 2018 Feb;1860(2):257-263. doi: 10.1016/j.bbamem.2017.10.019. Epub 2017 Oct 19.


Discovering how membrane proteins recognize signals and passage molecules remains challenging. Life depends on compartmentalizing these processes into dynamic lipid bilayers that are technically difficult to work with. Several polymers have proven adept at separating the responsible machines intact for detailed analysis of their structures and interactions. Styrene maleic acid (SMA) co-polymers efficiently solubilize membranes into native nanodiscs and, unlike amphipols and membrane scaffold proteins, require no potentially destabilizing detergents. Here we review progress with the SMA lipid particle (SMALP) system and its impacts including three dimensional structures and biochemical functions of peripheral and transmembrane proteins. Polymers systems are emerging to tackle the remaining challenges for wider use and future applications including in membrane proteomics, structural biology of transient or unstable states, and discovery of ligand and drug-like molecules specific for native lipid-bound states.

Keywords: Lipid bilayer; Membrane solubilization; Native nanodiscs; SMALP; Styrene maleic acid; Transmembrane protein.

Publication types

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

MeSH terms

  • Cell Membrane / chemistry*
  • Cell Membrane / metabolism
  • Lipid Bilayers / chemistry*
  • Lipid Bilayers / metabolism
  • Maleates / chemistry*
  • Maleates / metabolism
  • Membrane Proteins / chemistry
  • Membrane Proteins / metabolism
  • Models, Molecular
  • Molecular Structure
  • Nanostructures / chemistry*
  • Polystyrenes / chemistry*
  • Polystyrenes / metabolism
  • Protein Conformation
  • Solubility


  • Lipid Bilayers
  • Maleates
  • Membrane Proteins
  • Polystyrenes
  • styrene-maleic acid polymer