title: Modulating bilayer mechanical properties to promote the coupled folding and insertion of an integral membrane protein.
abstract: Bilayer mechanical properties are not only of crucial importance to the mechanism of action of mechanosensation in lipid membranes but also affect preparative laboratory tasks such as membrane-protein refolding. We report this for coupled refolding and bilayer insertion of outer membrane phospholipase A (OmpLA), an integral membrane enzyme that catalyses the hydrolytic cleavage of glycerophospholipids. OmpLA can be refolded into a variety of detergent micelles and unilamellar vesicles composed of short-chain phospholipids but, in the absence of chemical or molecular chaperones, not into thicker membranes. Controlled modulation of bilayer mechanical properties by judicious use of subsolubilising concentrations of detergents induces monolayer curvature strain, acyl chain fluidisation, membrane thinning, and transient aqueous bilayer defects. This enables quantitative and functional refolding of OmpLA even into bilayer membranes composed of long-chain phospholipids to yield enzymatically active proteoliposomes without requiring membrane solubilisation.
authors.affiliation: Molecular Biophysics, University of Kaiserslautern, Erwin-Schrödinger-Str. 13, 67663, Kaiserslautern, Germany.
authors.forename: Michaela
authors.initials: M
authors.lastname: Herrmann
authors.forename: Bartholomäus
authors.initials: B
authors.lastname: Danielczak
authors.forename: Martin
authors.initials: M
authors.lastname: Textor
authors.forename: Jessica
authors.initials: J
authors.lastname: Klement
authors.forename: Sandro
authors.initials: S
authors.lastname: Keller
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D001696:Biomechanical Phenomena; D003902:Detergents / Q000494:pharmacology; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism*; D054466:Phospholipases A1 / Q000737:chemistry / Q000378:metabolism*; D017510:Protein Folding; D053835:Unilamellar Liposomes / Q000378:metabolism
chemical_list: D001425:Bacterial Outer Membrane Proteins; D003902:Detergents; D008051:Lipid Bilayers; D053835:Unilamellar Liposomes; D054466:Phospholipases A1; C412876:outer membrane phospholipase A