Use of a Poly-γ-Glutamic Acid-Derived Amphipathic Polypeptide for the Reconstitution of Membrane Proteins

摘要

Membrane proteins including G-protein coupled receptors (GPCRs) or channels constitute ~30% of eukaryotic proteins and are targets for approximately half of the drags on the market since they play irreplaceable roles in living organisms. Despite their importance, fundamental studies, as well as pharmacological applications of membrane proteins, have been hindered by several obstacles including the stabilization of their active conformations in vitro. Biochemical and biophysical characterizations of purified membrane proteins require the stabilization of the membrane proteins in then-native or active conformation. Using detergents to target membrane proteins is a common method used to reconstitute the proteins' active conformations in an aqueous solution. Recently, maltose-neopentyl glycol (MNG) amphiphiles and a bicelle-like architecture formed after mixing n-dodecyl-β-D-maltoside (DDM) with cholesteryl hemisuccinate (CHS) have been successfully used for the stabilization and reconstitution of membrane proteins.~(1,2) Although mild detergents containing a sugar moiety, such as DDM and P-octylglucoside (POG), are preferred for such reactions, screening of various detergents is essential since a detergent suitable for maintaining the active conformation of one particular membrane protein need not necessarily be useful for other membrane proteins.