title: Structural evidence for a programmed general base in the active site of a catalytic antibody.
abstract: The crystal structure of the complex of a catalytic antibody with its cationic hapten at 1.9-A resolution demonstrates that the hapten amidinium group is stabilized through an ionic pair interaction with the carboxylate of a combining-site residue. The location of this carboxylate allows it to act as a general base in an allylic rearrangement. When compared with structures of other antibody complexes in which the positive moiety of the hapten is stabilized mostly by cation-pi interactions, this structure shows that the amidinium moiety is a useful candidate to elicit a carboxylate in an antibody combining site at a predetermined location with respect to the hapten. More generally, this structure highlights the advantage of a bidentate hapten for the programmed positioning of a chemically reactive residue in an antibody through charge complementarity to the hapten.
authors.affiliation: Laboratoire d'Enzymologie et Biochimie Structurales, Centre National de la Recherche Scientifique, Bâtiment 34, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, France. beatrice.golinelli@lebs.cnrs-gif.fr
authors.forename: B
authors.initials: B
authors.lastname: Golinelli-Pimpaneau
authors.forename: O
authors.initials: O
authors.lastname: Goncalves
authors.forename: T
authors.initials: T
authors.lastname: Dintinger
authors.forename: D
authors.initials: D
authors.lastname: Blanchard
authors.forename: M
authors.initials: M
authors.lastname: Knossow
authors.forename: C
authors.initials: C
authors.lastname: Tellier
mesh_terms: D000595:Amino Acid Sequence; D017151:Antibodies, Catalytic / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D018360:Crystallography, X-Ray; D006241:Haptens / Q000737:chemistry; D007140:Immunoglobulin Fab Fragments / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation
chemical_list: D017151:Antibodies, Catalytic; D006241:Haptens; D007140:Immunoglobulin Fab Fragments