PMID: 10880560 , Related PDB ids: 1F4W, 1F4X, 1F4Y

Authors:

Villeneuve S, Souchon H, Riottot MM, Mazie JC, Lei P, Glaudemans CP, Kovac P, Fournier JM, Alzari PM

Title:

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

Journal:

Proc Natl Acad Sci U S A. 2000 Jul 18;97(15):8433-8.

Abstract:

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.