 |
PDBsum entry 1f4x
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Immune system
|
PDB id
|
|
|
|
1f4x
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
Contents |
 |
|
|
|
|
|
|
|
|
|
|
|
|
* Residue conservation analysis
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
Crystal structure of an anti-Carbohydrate antibody directed against vibrio cholerae o1 in complex with antigen: molecular basis for serotype specificity.
|
|
|
Authors
|
|
S.Villeneuve,
H.Souchon,
M.M.Riottot,
J.C.Mazie,
P.Lei,
C.P.Glaudemans,
P.Kovác,
J.M.Fournier,
P.M.Alzari.
|
|
|
Ref.
|
|
Proc Natl Acad Sci U S A, 2000,
97,
8433-8438.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
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.
|
|
|
|
|
|
|
|
Figure 2.
Fig. 2. Final (2F[o]  F[c])
electron density maps contoured at 1.5  for the
Ogawa monosaccharide and disaccharide fragments bound to the Ab
binding cleft. The methyl group at the O-2 position of the
terminal perosamine residue is indicated. Figure produced with
the program O (26).
|
|
Figure 4.
Fig. 4. Protein-carbohydrate interactions. The molecular
surface (colored according to charge) for the Fab fragment of
S-20-4 with the (a) monosaccharide and (b) disaccharide ligands.
(c) Close view of the bound monosaccharide, with the sugar ring
facing a central hydrophobic pocket and the tetronic acid moiety
occupying a shallow cavity formed by residues from the Ab heavy
chain. (d) Intermolecular hydrogen bonding interactions in the
Fab-disaccharide complex. [The hydrogen bond between the
carbonyl group of the upstream terminal sugar residue (arrow)
and the main chain NH group at position H98 is not shown.]
Figure produced with the program GRASP (41).
|
|
|
|
|
|
|
|
|
|
