Thermodynamic measurements of bilayer insertion of a single transmembrane helix chaperoned by fluorinated surfactants.

ABSTRACT: Accurate determination of the free energy of transfer of a helical segment from an aqueous into a transmembrane (TM) conformation is essential for understanding and predicting the folding and stability of membrane proteins. Until recently, direct thermodynamically sound measurements of free energy of insertion of hydrophobic TM peptides were impossible due to peptide aggregation outside the lipid bilayer. Here, we overcome this problem by using fluorinated surfactants that are capable of preventing aggregation but, unlike detergents, do not themselves interact with the bilayer. We have applied the fluorescence correlation spectroscopy methodology to study surfactant-chaperoned insertion into preformed POPC (palmitoyloleoylphosphatidylcholine) vesicles of the two well-studied dye-labeled TM

SUBMITTER: Kyrychenko A 

PROVIDER: S-EPMC3273640 | biostudies-literature | 2012 Feb

REPOSITORIES: biostudies-literature