Folding of β-Barrel Membrane Proteins into Lipid Membranes by Site-Directed Fluorescence Spectroscopy.

Folding of β-Barrel Membrane Proteins into Lipid Membranes by Site-Directed Fluorescence Spectroscopy. Methods Mol Biol. 2019;2003:465-492 Authors: Gerlach L, Gholami O, Schürmann N, Kleinschmidt JH Abstract Protein-lipid interactions are important for folding and membrane insertion of integral membrane proteins that are composed either of α-helical or of β-barrel structure in their transmembrane domains. While α-helical transmembrane proteins fold co-translationally while they are synthesized by a ribosome, β-barrel transmembrane proteins (β-TMPs) fold and insert posttranslationally-in bacteria after translocation across the cytoplasmic membrane, in cell organelles of eukaryotes after import across the outer membrane of the organelle. β-TMPs can be unfolded in aqueous solutions of chaotropic denaturants like urea and spontaneously refold upon denaturant dilution in the presence of preformed lipid bilayers. This facilitates studies on lipid interactions during folding into lipid bilayers. For several β-TMPs, the kinetics of folding has been reported as strongly dependent on protein-lipid interactions. The kinetics of adsorption/insertion and folding of β-TMPs can be monitored by fluorescence spectroscopy. These fluorescence methods are even more powerful when combined with site-directed mutagenesis for the preparation of mutants of a β-TMP that are site-specifically labeled with a fluorophore or a fluorophore and fluoresce...
Source: Mol Biol Cell - Category: Molecular Biology Authors: Tags: Methods Mol Biol Source Type: research