Structuring Detergents for Extracting and Stabilizing Functional Membrane Proteins
Figure 1
Concept of salt bridge network between anionic and amphiphilic molecules and basic residues located at the cytosol-membrane interface of membrane proteins.
(A) Scheme of a hypothetical dimeric membrane protein typically displaying basic residues at the cytosol-membrane interface, as established by von Heijne [24]. In the absence of lipids, the membrane domain remains in a native conformation due to compounds displaying detergent properties for keeping the membrane protein in solution (grey molecules), but also mild-anionic groups (black molecules), for generating a network of salt bridges close to the membrane domain with basic amino acids carried by the intracellular loops (or domains) of the membrane proteins. (B) Chemical structure of the designed molecules, C4Cn. Three aromatic rings are substituted by a methylene carboxyl group, -CH2COOH, at the para position. An aliphatic chain R, O(CH2)0-11CH3, is grafted onto the fourth phenolic group. The resulting 3D-structure is modelled from the crystal structure of nitrile derivatives [26], substituting the CN groups with carboxyl groups.