Major Outer Membrane Proteins of Escherichia coli Strains of Human Origin

Abstract

The major outer membrane protein patterns of 45 E. coli strains of human origin were compared with that of E. coli K12 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Preparations of the former strains contained 2-5 major bands in the MW range between 30,000-42,000. The patterns were heterogeneous with respect to the numbers and electrophoretic mobilities of the major outer membrane protein bands. In all cases the fastest moving band was characterized as a protein similar to the ompA protein of strain K12 as it was partially degraded by trypsin and reacted specifically with antiserum against the purified ompA protein in a gel immunoradioassay. All other major membrane proteins are related to the ompC and ompF proteins (the porins) of strain K12 as they were peptidoglycan-associated and reacted with antisera against the purified ompC and/or ompF proteins.