On the Antigenic Determinants of the Lipopolysaccharides of Vibrio cholerae O:1, Serotypes Ogawa and Inaba

• Published in: The Journal of biological chemistry Vol. 273; no. 5; pp. 2777 - 2783
• Main Authors: Wang, J, Villeneuve, S, Zhang, J, Lei, P, Miller, C E, Lafaye, P, Nato, F, Szu, S C, Karpas, A, Bystricky, S, Robbins, J B, Kovác, P, Fournier, J M, Glaudemans, C P
• Format: Journal Article
• Language: English
• Published: United States American Society for Biochemistry and Molecular Biology 30-01-1998
• Subjects: Amino Acid Sequence; Antibodies, Bacterial - genetics; Antibodies, Bacterial - immunology; Antibodies, Monoclonal - genetics; Antibody Specificity; Binding, Competitive; Cloning, Molecular; Epitopes; Immunoglobulin G - genetics; Immunoglobulin G - immunology; Ligands; Molecular Sequence Data; Monosaccharides - immunology; O Antigens - immunology; Oligosaccharides - immunology; Species Specificity; Vibrio cholerae - classification; Vibrio cholerae - immunology
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.273.5.2777

Monoclonal, murine IgG 1 s S-20-4, A-20-6, and IgA 2D6, directed against Vibrio cholerae O:1 Ogawa-lipopolysaccharide exhibited the same fine specificities and similar affinities for the synthetic methyl α-glycosides
of the (oligo)saccharide fragments mimicking the Ogawa O-polysaccharide (O-PS). They did not react with the corresponding
synthetic fragments of Inaba O-PS. IgG 1 s S-20-4 and A-20-6 have absolute affinity constants for synthetic Ogawa mono- to hexasaccharides of from ∼10 5 to ∼10 6
m
−1 . For IgG 1 s S-20-4, A-20-6, and IgA 2D6, the nonreducing terminal residue of Ogawa O-PS is the dominant determinant, accounting for
∼90% of the maximal binding energy shown by these antibodies. Binding studies of derivatives of the Ogawa monosaccharide and
IgGs S-20-4 and A-20-6 revealed that the C-2 O -methyl group fits into a somewhat flexible antibody cavity and that hydrogen bonds involving the oxygen and, respectively,
the OH at the 2- and 3-position of the sugar moiety as well as the 2′-position in the amide side chain are required.
Monoclonal IgA ZAC-3 and IgG 3 I-24-2 are specific for V. cholerae O:1 serotypes Ogawa/Inaba-LPS. 1 The former did not show binding with members of either series of the synthetic ligands related to the O-antigens of the Ogawa
or Inaba serotypes, in agreement with its reported specificity for the lipid/core region (1). Inhibition studies revealed
that the binding of purified IgG 3 I-24-2 to Ogawa-LPS might be mediated by a region in the junction of the OPS to the lipid-core region of the LPS.
cDNA cloning and analysis of the anti-Ogawa antibodies S-20-4, A-20-6, and 2D6 revealed a very high degree of homology among
the heavy chains. Among the light chains, no such homology between S-20-4 and A-20-6 on the one hand, and 2D6 on the other
hand, exists. For the anti-Inaba/Ogawa antibodies I-24-2 and ZAC-3, their heavy chains are completely different, with some
homology among the light chains.