title: Identification of the protein producing transmembrane diffusion pores in the outer membrane of Pseudomonas aeruginosa PA01.
abstract: The outer membrane of Pseudomonas aeruginosa PA01 is permeable to saccharides of molecular weights lower than about 6000. Triton X-100/EDTA-soluble outer membrane proteins were fractionated by ion-exchange chromatography in the presence of Triton X-100 and EDTA, and the protein contents of the various fractions analysed by sodium dodecyl sulphate polyacrylamide gel electrophoresis. Each of the major protein bands present in the Triton X-100/EDTA soluble outer membrane was separated from one another. Adjacent fractions were pooled, concentrated and extensively dialyzed to reduce the Triton X-100 concentration. Vesicles were reconstituted from lipopolysaccharide, phospholipids and each of these dialyzed fractions, and examined for their ability to retain [14C]sucrose. Control experiments indicated that the residual levels of Triton X-100 remaining in the dialyzed fractions had no effect on the formation or permeability to saccharides of the reconstituted vesicles. It was concluded that a major outer membrane polypeptide with an apparent weight of 35,000 is a porin, responsible for the size-dependent permeability of the outer membrane.
mesh_terms: D002462:Cell Membrane / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D008070:Lipopolysaccharides / Q000032:analysis; D008563:Membrane Lipids / Q000032:analysis; D008565:Membrane Proteins / Q000032:analysis*; D008970:Molecular Weight; D010743:Phospholipids / Q000032:analysis; D011092:Polyethylene Glycols; D011550:Pseudomonas aeruginosa / Q000032:analysis*
chemical_list: D008070:Lipopolysaccharides; D008563:Membrane Lipids; D008565:Membrane Proteins; D010743:Phospholipids; D011092:Polyethylene Glycols