title: Channel-forming properties and structural homology of major outer membrane proteins from Pseudomonas fluorescens MFO and OE 28.3.
abstract: The major outer membrane proteins (OprF) from Pseudomonas fluorescens MFO and OE 28.3 were purified by a new method involving native electrophoresis in octyl-polyoxyethylene media. Both proteins, characterized by the same size, heat-modifiability and N-terminal sequence were re-incorporated in virtually solvent-free planar lipid bilayers. They displayed very similar channel-forming properties: the major conductance level was between 250 pS and 270 pS in 1 M NaCl. From experiments of zero-current potential, both porins were determined weakly cation selective. Amplification by PCR and sequencing of the oprF gene of strain MFO allowed to point out 94% identity between the amino acid sequences of these two OprFs isolated from ecological niches as different as milk (strain MFO) and soil (strain OE 28.3).
authors.affiliation: URA 500 CNRS, Faculté des Sciences de Rouen, Mont-Saint-Aignan, France.
authors.forename: E
authors.initials: E
authors.lastname: Dé
authors.forename: R
authors.initials: R
authors.lastname: De Mot
authors.forename: N
authors.initials: N
authors.lastname: Orange
authors.forename: N
authors.initials: N
authors.lastname: Saint
authors.forename: G
authors.initials: G
authors.lastname: Molle
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D004553:Electric Conductivity; D007473:Ion Channels / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008051:Lipid Bilayers; D008892:Milk / Q000382:microbiology; D008969:Molecular Sequence Data; D015394:Molecular Structure; D016133:Polymerase Chain Reaction; D018272:Porins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011551:Pseudomonas fluorescens / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D012988:Soil Microbiology; D013045:Species Specificity
chemical_list: D007473:Ion Channels; D008051:Lipid Bilayers; D018272:Porins