Crystal structure of an anti-carbohydrate antibody directed against Vibrio cholerae O1 in complex with antigen: Molecular basis for serotype specificity

S Villeneuve, H Souchon, MM Riottot… - Proceedings of the …, 2000 - National Acad Sciences
S Villeneuve, H Souchon, MM Riottot, JC Mazié, P Lei, CPJ Glaudemans, P Kováč
Proceedings of the National Academy of Sciences, 2000National Acad Sciences
The crystal structure of the murine Fab S-20-4 from a protective anti-cholera Ab specific for
the lipopolysaccharide Ag of the Ogawa serotype has been determined in its unliganded
form and in complex with synthetic fragments of the Ogawa O-specific polysaccharide (O-
SP). The upstream terminal O-SP monosaccharide is shown to be the primary antigenic
determinant. Additional perosamine residues protrude outwards from the Ab surface and
contribute only marginally to the binding affinity and specificity. A complementary water …
The crystal structure of the murine Fab S-20-4 from a protective anti-cholera Ab specific for the lipopolysaccharide Ag of the Ogawa serotype has been determined in its unliganded form and in complex with synthetic fragments of the Ogawa O-specific polysaccharide (O-SP). The upstream terminal O-SP monosaccharide is shown to be the primary antigenic determinant. Additional perosamine residues protrude outwards from the Ab surface and contribute only marginally to the binding affinity and specificity. A complementary water-excluding hydrophobic interface and five Ab–Ag hydrogen bonds are crucial for carbohydrate recognition. The structure reported here explains the serotype specificity of anti-Ogawa Abs and provides a rational basis toward the development of a synthetic carbohydrate-based anti-cholera vaccine.
National Acad Sciences