An improved tripod amphiphile for membrane protein solubilization.

PubMed ID: 11206073

Author(s): Yu SM, McQuade DT, Quinn MA, Hackenberger CP, Krebs MP, Polans AS, Gellman SH. An improved tripod amphiphile for membrane protein solubilization. Protein Sci. 2000 Dec;9(12):2518-27. PMID 11206073

Journal: Protein Science : A Publication Of The Protein Society, Volume 9, Issue 12, Dec 2000

Intrinsic membrane proteins represent a large fraction of the proteins produced by living organisms and perform many crucial functions. Structural and functional characterization of membrane proteins generally requires that they be extracted from the native lipid bilayer and solubilized with a small synthetic amphiphile, for example, a detergent. We describe the development of a small molecule with a distinctive amphiphilic architecture, a “tripod amphiphile,” that solubilizes both bacteriorhodopsin (BR) and bovine rhodopsin (Rho). The polar portion of this amphiphile contains an amide and an amine-oxide; small variations in this polar segment are found to have profound effects on protein solubilization properties. The optimal tripod amphiphile extracts both BR and Rho from the native membrane environments and maintains each protein in a monomeric native-like form for several weeks after delipidation. Tripod amphiphiles are designed to display greater conformational rigidity than conventional detergents, with the long-range goal of promoting membrane protein crystallization. The results reported here represent an important step toward that ultimate goal.