1yej: Difference between revisions
New page: left|200px<br /> <applet load="1yej" size="450" color="white" frame="true" align="right" spinBox="true" caption="1yej, resolution 1.85Å" /> '''CATALYTIC ANTIBODY ... |
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[[Image:1yej. | [[Image:1yej.jpg|left|200px]]<br /><applet load="1yej" size="350" color="white" frame="true" align="right" spinBox="true" | ||
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'''CATALYTIC ANTIBODY COMPLEX'''<br /> | '''CATALYTIC ANTIBODY COMPLEX'''<br /> | ||
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==About this Structure== | ==About this Structure== | ||
1YEJ is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] with ZN and PNF as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | 1YEJ is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] with <scene name='pdbligand=ZN:'>ZN</scene> and <scene name='pdbligand=PNF:'>PNF</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1YEJ OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: transition state analog]] | [[Category: transition state analog]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri Feb 15 17:11:51 2008'' | ||
Revision as of 18:11, 15 February 2008
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CATALYTIC ANTIBODY COMPLEX
OverviewOverview
The antibody D2.3 catalyzes the hydrolysis of several p-nitrobenzyl and, p-nitrophenyl esters with significant rate enhancement; product inhibition, is observed with the former compounds but not with the latter. Whereas, enzyme specificity has been extensively studied by X-ray crystallography, structural data on catalytic antibodies have thus far related only to one, of the reactions they catalyze. To investigate the substrate specificity, and the substrate relative to product selectivity of D2.3, we have, determined the structures of its complexes with two p-nitrophenyl, phosphonate transition state analogs (TSAs) and with the reaction product, p-nitrophenol. The complexes with these TSAs, determined at 1.9 A, resolution, and that with p-nitrobenzyl phosphonate determined previously, differ mainly by the locations and conformations of the ligands. Taken, together with kinetic data, the structures suggest that a hydrogen bond to, an atom of the substrate distant by eight covalent bonds from the carbonyl, group of the hydrolyzed ester bond contributes to catalytic efficiency and, substrate specificity. The structure of Fab D2.3 complexed with, p-nitrophenol was determined at 2.1 A resolution. Release of p-nitrophenol, is facilitated due to the unfavourable interaction of the partial charge, of the nitro group of p-nitrophenolate with the hydrophobic cavity where, it is located, and to the absence of a direct hydrogen bond between the, product and the Fab. Catalytic specificity and the manner of product, release are both affected by interactions with substrate atoms remote from, the reaction center that were not programmed in the design of the TSA used, to elicit this antibody. Selection of a catalytic antibody that makes use, of TSA unprogrammed features has been made practical because of the, screening for catalytic efficiency incorporated in the procedure used to, obtain it.
About this StructureAbout this Structure
1YEJ is a Protein complex structure of sequences from Mus musculus with and as ligands. Full crystallographic information is available from OCA.
ReferenceReference
Crossreactivity, efficiency and catalytic specificity of an esterase-like antibody., Gigant B, Charbonnier JB, Eshhar Z, Green BS, Knossow M, J Mol Biol. 1998 Dec 4;284(3):741-50. PMID:9826512
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