title: Post-expression strategies for structural investigations of membrane proteins.
abstract: 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.
authors.affiliation: Department of Chemistry, University of Virginia, Charlottesville, VA 22902, United States. Electronic address: columbus@virginia.edu.
authors.forename: Linda
authors.initials: L
authors.lastname: Columbus
mesh_terms: D000478:Alkylation; D000818:Animals; D002240:Carbohydrate Sequence; D003460:Crystallization / Q000379:methods; D018360:Crystallography, X-Ray / Q000379:methods; D003545:Cysteine / Q000737:chemistry; D006031:Glycosylation; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D011487:Protein Conformation; D059748:Proteolysis
chemical_list: D008565:Membrane Proteins; D003545:Cysteine