title: Associations of Escherichia coli K-12 OmpF trimers with rough and smooth lipopolysaccharides.
abstract: The associations of both rough and smooth lipopolysaccharides (LPS) with the OmpF porin of Escherichia coli K-12 were examined in galE strains deleted for ompC. Transformation with pSS37 and growth with galactose conferred the ability to assemble a Shigella dysenteriae O antigen onto the core oligosaccharide of E. coli K-12 LPS. The association of LPS with OmpF trimers was assessed by staining, autoradiography of LPS specifically labeled with [1-14C]galactose, and Western immunoblotting with a monoclonal antibody specific for OmpF trimers. These techniques revealed that the migration distances and multiple banding patterns of OmpF porin trimers in sodium dodecyl sulfate-polyacrylamide gels were dictated by the chemotype of associated LPS. Expression of smooth LPS caused almost all of the trimeric OmpF to run in gels with a slower mobility than trimers from rough strains. The LPS associated with trimers from a smooth strain differed from the bulk-phase LPS by consisting almost exclusively of molecules with O antigen.
authors.affiliation: Department of Microbiology, Immunology, and Parasitology, Louisiana State University Medical Center, New Orleans 70112-1393.
authors.forename: D L
authors.initials: DL
authors.lastname: Diedrich
authors.forename: M A
authors.initials: MA
authors.lastname: Stein
authors.forename: C A
authors.initials: CA
authors.lastname: Schnaitman
mesh_terms: D001345:Autoradiography; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000302:isolation & purification*; D015153:Blotting, Western; D002250:Carbon Radioisotopes; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D005690:Galactose / Q000378:metabolism; D008070:Lipopolysaccharides / Q000302:isolation & purification*; D046911:Macromolecular Substances; D018272:Porins
chemical_list: D001425:Bacterial Outer Membrane Proteins; D002250:Carbon Radioisotopes; D008070:Lipopolysaccharides; D046911:Macromolecular Substances; D018272:Porins; D005690:Galactose