Channel-forming properties and structural homology of major outer membrane proteins from Pseudomonas fluorescens MFO and OE 28.3

FEMS Microbiol Lett. 1995 Apr 1;127(3):267-72. doi: 10.1111/j.1574-6968.1995.tb07484.x.


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).

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cattle
  • Electric Conductivity
  • Ion Channels / chemistry
  • Ion Channels / genetics
  • Ion Channels / metabolism*
  • Lipid Bilayers
  • Milk / microbiology
  • Molecular Sequence Data
  • Molecular Structure
  • Polymerase Chain Reaction
  • Porins / chemistry
  • Porins / genetics
  • Porins / metabolism*
  • Pseudomonas fluorescens / genetics
  • Pseudomonas fluorescens / isolation & purification
  • Pseudomonas fluorescens / metabolism*
  • Sequence Homology, Amino Acid
  • Soil Microbiology
  • Species Specificity


  • Ion Channels
  • Lipid Bilayers
  • Porins

Associated data

  • GENBANK/U19743