Determination of the immunodominant part in the O-antigenic polysaccharidefrom Escherichia coli O128 by ELISA-inhibition study

The immunodominant part in the O-antigenic polysaccharide from Escherichia coil O128 was immunologically characterized by an enzyme-linked immunosorbe nt assay (ELISA). The antibody specificity was determined by the inhibitory effects of the methyl glycosides of constituent mono- and oligosaccharides synthesized related to the O-antigenic polysaccharide from E. coli O128. I t was found that methyl alpha-L-fucopyranoside was the most effective inhib itor amongst the monosaccharides while the highest antibody specificity was directed towards the trisaccharide with the structure: beta-D-GalpNAc-(1 - -> 6)-[alpha-L-Fucp-(1 --> 2)]-beta-D-Galp-1 --> OMe suggesting that the mo nospecific antibody has the extended combining site. (C) 2000 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.