title: Strain specificity of outer membrane proteins in Escherichia coli.
abstract: Outer membrane proteins of various strains of Escherichia coli were compared using three different systems of sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. The outer membranes of E. coli K-12, E. coli B, and E. coli J-5 had distinctive protein compositions. As regards proteins which interact with peptidoglycan, E. coli K-12 contained O-8 and O-9, while E. coli B possessed one protein which migrated to the position of O-9. Although E. coli J-5 possessed two such proteins, O-8' and O-9', their positions on polyacrylamide gel were different from those of O-8 and O-9. Protein O-7, which migrates slightly more slowly than O-8, was found specifically in E. coli K-12. Proteins O-10 and O-11 were found in all strains tested, although the relative amounts were different depending on the strain. Strains of E. coli K-12 and E. coli J-5 gave three major bands, O-2a, O-2b, and O-3, in the region of high molecular weight. These proteins were repressed by iron in the cultivation media. Strains of E. coli B, on the other hand, gave only O-2b and O-3. E. coli J-5 gave two other major bands in this region, but the amounts were not controlled by iron in the cultivation media.
mesh_terms: D002462:Cell Membrane / Q000032:analysis*; D004589:Electrophoresis, Disc; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000032:analysis*; D005838:Genotype; D008565:Membrane Proteins / Q000302:isolation & purification / Q000378:metabolism; D008970:Molecular Weight; D009154:Mutation; D010457:Peptidoglycan / Q000378:metabolism; D013045:Species Specificity
chemical_list: D008565:Membrane Proteins; D010457:Peptidoglycan