Post-expression strategies for structural investigations of membrane proteins

Curr Opin Struct Biol. 2015 Jun;32:131-8. doi: 10.1016/ Epub 2015 May 16.


Currently, membrane proteins only comprise 1.5% of the protein data bank and, thus, still remain a challenge for structural biologists. Expression, stabilization in membrane mimics (e.g. detergent), heterogeneity (conformational and chemical), and crystallization in the presence of a membrane mimic are four major bottlenecks encountered. In response, several post-expression protein modifications have been utilized to facilitate structure determination of membrane proteins. This review highlights four approaches: limited proteolysis, deglycosylation, cysteine alkylation, and lysine methylation. Combined these approaches have facilitated the structure determination of more than 40 membrane proteins and, therefore, are a useful addition to the membrane protein structural biologist's toolkit.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Alkylation
  • Animals
  • Carbohydrate Sequence
  • Crystallization / methods
  • Crystallography, X-Ray / methods
  • Cysteine / chemistry
  • Glycosylation
  • Humans
  • Membrane Proteins / chemistry*
  • Models, Molecular
  • Molecular Sequence Data
  • Nuclear Magnetic Resonance, Biomolecular / methods
  • Protein Conformation
  • Proteolysis


  • Membrane Proteins
  • Cysteine