title: Membrane Protein Solubilization and Composition of Protein Detergent Complexes.
abstract: Membrane proteins are typically expressed in heterologous systems with a view to in vitro characterization. A critical step in the preparation of membrane proteins after expression in any system is the solubilization of the protein in aqueous solution, typically using detergents and lipids, to obtain the protein in a form suitable for purification, structural or functional analysis. This process is particularly difficult as the objective is to prepare the protein in an unnatural environment, a protein detergent complex, separating it from its natural lipid partners while causing the minimum destabilization or modification of the structure. Although the process is difficult, and relatively hard to master, an increasing number of membrane proteins have been successfully isolated after expression in a wide variety of systems. In this chapter we give a general protocol for preparing protein detergent complexes that is aimed at guiding the reader through the different critical steps. In the second part of the chapter we illustrate how to analyze the composition of protein detergent complexes; this analysis is important as it has been found that compositional variation often causes irreproducible results.
authors.affiliation: AIX Marseille Université, Centrale Marseille, CNRS, iSm2 UMR 7313, Marseille, 13397, France.
authors.forename: Katia
authors.initials: K
authors.lastname: Duquesne
authors.affiliation: LISM UMR 7255, CNRS, Aix-Marseille Université, 31 Chemin Joseph Aiguier, 13402, Marseille, France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Prima
authors.affiliation: LISM UMR 7255, CNRS, Aix-Marseille Université, 31 Chemin Joseph Aiguier, 13402, Marseille, France. james.sturgis@univ-amu.fr.
authors.forename: James N
authors.initials: JN
authors.lastname: Sturgis
mesh_terms: D001419:Bacteria / Q000235:genetics / Q000254:growth & development; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D003902:Detergents / Q000737:chemistry*; D008565:Membrane Proteins / Q000737:chemistry*; D055503:Protein Multimerization; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D003902:Detergents; D008565:Membrane Proteins
keywords: Density gradient; FTIR; Lipid analysis