Antigenic polymorphism of the LamB protein among members of the family Enterobacteriaceae

In this study we demonstrate that most members of the family Enterobacteriaceae possess a maltose-inducible outer membrane protein homologous to the LamB protein of Escherichia coli K-12. These proteins react with polyclonal antibodies raised against the LamB protein of E. coli K-12. We compared the antigenic structure of the LamB protein in members of the family Enterobacteriaceae with six monoclonal antibodies raised against the LamB protein of E. coli K-12. Four of them reacted with epitopes located at the outer face of the membrane, and two reacted with epitopes located at the inner face of the membrane. A great degree of variability was observed for the external epitopes. Even in a single species, such as E. coli, an important polymorphism was present. In contrast, the internal epitopes were more conserved.