Immunological relatedness of the LamB proteins among members of Enterobacteriaceae.

We have studied the immunological relatedness of LamB proteins from a wide range of enterobacterial species, using antibodies directed against denatured Escherichia coli K12 and Klebsiella pneumoniae LamB proteins (LamBE.c. and LamBK.p., respectively), and anti-peptide antibodies directed against 10 distinct loops of LamB from E. coli K12 predicted to protrude either side of the outer membrane. We have shown that a protein immunologically related to LamBE.c. and LamBK.p. was present in all members of Enterobacteriaceae tested. A protein recognized by several anti-peptide antibodies was identified in E. coli, Shigella sonnei, Salmonella typhimurium and Kleb. pneumoniae, as well as in two Citrobacter species, two Enterobacter species and Kluyvera ascorbata. The recognition patterns obtained with the anti-peptide antibodies were in agreement with the LamB protein sequence data available. They indicated that the cell surface and also the periplasmic loops of LamB are subject to great antigenic variability.