1e4x
From Proteopedia
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| - | [[Image:1e4x.gif|left|200px]] | + | [[Image:1e4x.gif|left|200px]] |
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| - | '''CROSSREACTIVE BINDING OF A CIRCULARIZED PEPTIDE TO AN ANTI-TGFALPHA ANTIBODY FAB-FRAGMENT''' | + | {{Structure |
| + | |PDB= 1e4x |SIZE=350|CAPTION= <scene name='initialview01'>1e4x</scene>, resolution 1.9Å | ||
| + | |SITE= | ||
| + | |LIGAND= | ||
| + | |ACTIVITY= | ||
| + | |GENE= | ||
| + | }} | ||
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| + | '''CROSSREACTIVE BINDING OF A CIRCULARIZED PEPTIDE TO AN ANTI-TGFALPHA ANTIBODY FAB-FRAGMENT''' | ||
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==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1E4X is a [ | + | 1E4X is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1E4X OCA]. |
==Reference== | ==Reference== | ||
| - | Cross-reactive binding of cyclic peptides to an anti-TGFalpha antibody Fab fragment: an X-ray structural and thermodynamic analysis., Hahn M, Winkler D, Welfle K, Misselwitz R, Welfle H, Wessner H, Zahn G, Scholz C, Seifert M, Harkins R, Schneider-Mergener J, Hohne W, J Mol Biol. 2001 Nov 23;314(2):293-309. PMID:[http:// | + | Cross-reactive binding of cyclic peptides to an anti-TGFalpha antibody Fab fragment: an X-ray structural and thermodynamic analysis., Hahn M, Winkler D, Welfle K, Misselwitz R, Welfle H, Wessner H, Zahn G, Scholz C, Seifert M, Harkins R, Schneider-Mergener J, Hohne W, J Mol Biol. 2001 Nov 23;314(2):293-309. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/11718562 11718562] |
[[Category: Mus musculus]] | [[Category: Mus musculus]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
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[[Category: protein-peptide recognition]] | [[Category: protein-peptide recognition]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 10:49:47 2008'' |
Revision as of 08:49, 20 March 2008
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| Coordinates: | save as pdb, mmCIF, xml | ||||||
CROSSREACTIVE BINDING OF A CIRCULARIZED PEPTIDE TO AN ANTI-TGFALPHA ANTIBODY FAB-FRAGMENT
Overview
The monoclonal antibody tAb2 binds the N-terminal sequence of transforming growth factor alpha, VVSHFND. With the help of combinatorial peptide libraries it is possible to find homologous peptides that bind tAb2 with an affinity similar to that of the epitope. The conformational flexibility of short peptides can be constrained by cyclization in order to improve their affinity to the antibody and their stability towards proteolysis. Two cyclic peptides which are cross-reactive binders for tAb2 were selected earlier using combinatorial peptide libraries. One is cyclized by an amide bond between the N-alpha group and the side-chain of the last residue (cyclo-SHFNEYE), and the other by a disulfide bridge (cyclo-CSHFNDYC). The complex structures of tAb2 with the linear epitope peptide VVSHFND and with cyclo-SHFNEYE were determined by X-ray diffraction. Both peptides show a similar conformation and binding pattern in the complex. The linear peptide SHFNEYE does not bind tAb2, but cyclo-SHFNEYE is stabilized in a loop conformation suitable for binding. Hence the cyclization counteracts the exchange of aspartate in the epitope sequence to glutamate. Isothermal titration calorimetry was used to characterize the binding energetics of tAb2 with the two cyclic peptides and the epitope peptide. The binding reactions are enthalpically driven with an unfavorable entropic contribution under all measured conditions. The association reactions are characterized by negative DeltaC(p) changes and by the uptake of one proton per binding site. A putative candidate for proton uptake during binding is the histidine residue in each of the peptides. Hydrogen bonds and the putative formation of an electrostatic pair between the protonated histidine and a carboxy group may contribute markedly to the favorable enthalpy of complex formation.Implications to cyclization of peptides for stabilization are discussed.
About this Structure
1E4X is a Protein complex structure of sequences from Mus musculus. Full crystallographic information is available from OCA.
Reference
Cross-reactive binding of cyclic peptides to an anti-TGFalpha antibody Fab fragment: an X-ray structural and thermodynamic analysis., Hahn M, Winkler D, Welfle K, Misselwitz R, Welfle H, Wessner H, Zahn G, Scholz C, Seifert M, Harkins R, Schneider-Mergener J, Hohne W, J Mol Biol. 2001 Nov 23;314(2):293-309. PMID:11718562
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