title: Folding of outer membrane protein A in the anionic biosurfactant rhamnolipid.
abstract: Folding and stability of bacterial outer membrane proteins (OMPs) are typically studied in vitro using model systems such as phospholipid vesicles or surfactant. OMP folding requires surfactant concentrations above the critical micelle concentration (cmc) and usually only occurs in neutral or zwitterionic surfactants, but not in anionic or cationic surfactants. Various Gram-negative bacteria produce the anionic biosurfactant rhamnolipid. Here we show that the OMP OmpA can be folded in rhamnolipid at concentrations above the cmc, though the thermal stability is reduced compared to the non-ionic surfactant dodecyl maltoside. We discuss implications for possible interactions between OMPs and biosurfactants in vivo.
authors.affiliation: iNANO, Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 14, DK - 8000 Aarhus C, Denmark. Electronic address: kell.andersen@inano.au.dk.
authors.forename: Kell K
authors.initials: KK
authors.lastname: Andersen
authors.affiliation: iNANO, Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 14, DK - 8000 Aarhus C, Denmark. Electronic address: dao@inano.au.dk.
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Otzen
mesh_terms: D000838:Anions / Q000737:chemistry / Q000378:metabolism; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry* / Q000378:metabolism; D002942:Circular Dichroism; D004591:Electrophoresis, Polyacrylamide Gel; D006017:Glycolipids / Q000737:chemistry* / Q000378:metabolism; D006090:Gram-Negative Bacteria / Q000378:metabolism; D007700:Kinetics; D017510:Protein Folding; D055550:Protein Stability; D013056:Spectrophotometry, Ultraviolet; D013501:Surface-Active Agents / Q000737:chemistry* / Q000378:metabolism; D013696:Temperature
chemical_list: D000838:Anions; D001425:Bacterial Outer Membrane Proteins; D006017:Glycolipids; D013501:Surface-Active Agents; C418382:rhamnolipid; C078167:OMPA outer membrane proteins
keywords: Biosurfactant; Folding; OmpA; Outer membrane protein; Rhamnolipid; Surfactant