Download MendeleyCrystal structure of the complex of a catalytic antibody Fab fragment with a transition state analog: structural similarities in esterase-like catalytic antibodies.
Charbonnier, J.B., Carpenter, E., Gigant, B., Golinelli-Pimpaneau, B., Eshhar, Z., Green, B.S., Knossow, M.(1995) Proc Natl Acad Sci U S A 92: 11721-11725
- PubMed: 8524836
- DOI: https://doi.org/10.1073/pnas.92.25.11721
- Primary Citation of Related Structures:
1KNO - PubMed Abstract:
The x-ray structure of the complex of a catalytic antibody Fab fragment with a phosphonate transition-state analog has been determined. The antibody (CNJ206) catalyzes the hydrolysis of p-nitrophenyl esters with significant rate enhancement and substrate specificity. Comparison of this structure with that of the uncomplexed Fab fragment suggests hapten-induced conformational changes: the shape of the combining site changes from a shallow groove in the uncomplexed Fab to a deep pocket where the hapten is buried. Three hydrogen-bond donors appear to stabilize the charged phosphonate group of the hapten: two NH groups of the heavy (H) chain complementarity-determining region 3 (H3 CDR) polypeptide chain and the side-chain of histidine-H35 in the H chain (His-H35) in the H1 CDR. The combining site shows striking structural similarities to that of antibody 17E8, which also has esterase activity. Both catalytic antibody ("abzyme") structures suggest that oxyanion stabilization plays a significant role in their rate acceleration. Additional catalytic groups that improve efficiency are not necessarily induced by the eliciting hapten; these groups may occur because of the variability in the combining sites of different monoclonal antibodies that bind to the same hapten.
Organizational Affiliation:
Laboratoire de Biologie Structurale, Centre National de la Recherche Scientifique, Université Paris Sud, Gif-sur-Yvette, France.
