1kno
From Proteopedia
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CRYSTAL STRUCTURE OF THE COMPLEX OF A CATALYTIC ANTIBODY FAB WITH A TRANSITION STATE ANALOG: STRUCTURAL SIMILARITIES IN ESTERASE-LIKE ABZYMES
Overview
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.
About this Structure
1KNO is a Protein complex structure of sequences from Mus musculus with ZN and PNP as ligands. Full crystallographic information is available from OCA.
Reference
Crystal structure of the complex of a catalytic antibody Fab fragment with a transition state analog: structural similarities in esterase-like catalytic antibodies., Charbonnier JB, Carpenter E, Gigant B, Golinelli-Pimpaneau B, Eshhar Z, Green BS, Knossow M, Proc Natl Acad Sci U S A. 1995 Dec 5;92(25):11721-5. PMID:8524836
Page seeded by OCA on Sun Nov 18 09:35:14 2007
