1yc7
From Proteopedia
(New page: 200px<br /> <applet load="1yc7" size="450" color="white" frame="true" align="right" spinBox="true" caption="1yc7, resolution 1.6Å" /> '''cAbAn33 VHH fragment...) |
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| - | [[Image:1yc7.gif|left|200px]]<br /> | + | [[Image:1yc7.gif|left|200px]]<br /><applet load="1yc7" size="350" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="1yc7" size=" | + | |
caption="1yc7, resolution 1.6Å" /> | caption="1yc7, resolution 1.6Å" /> | ||
'''cAbAn33 VHH fragment against VSG'''<br /> | '''cAbAn33 VHH fragment against VSG'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Heavy chain only antibodies of camelids bind their antigens with a single | + | Heavy chain only antibodies of camelids bind their antigens with a single domain, the VHH, which acquired adaptations relative to classical VHs to function in the absence of a VL partner. Additional CDR loop conformations, outside the canonical loop structures of VHs, broaden the repertoire of the antigen-binding site. The combined effects of part of the CDR3 that folds over the "former" VL binding site and framework-2 mutations to more hydrophilic amino acids, enhance the solubility of VHH domains and prevent VL pairing. cAbAn33, a VHH domain specific for the carbohydrate moiety of the variant surface glycoprotein of trypanosomes, has a short CDR3 loop that does not cover the former VL binding site as well as a VH-specific Trp47 instead of the VHH-specific Gly47. Resurfacing its framework-2 region (mutations Tyr37Val, Glu44Gly and Arg45Leu) to mimic that of a human VH restores the VL binding capacity. In solution, the humanised VHH behaves as a soluble, monomeric entity, albeit with reduced thermodynamic stability and affinity for its antigen. Comparison of the crystal structures of cAbAn33 and its humanised derivative reveals steric hindrance exerted by VHH-specific residues Tyr37 and Arg45 that prevent the VL domain pairing, whereas Glu44 and Arg45 are key elements to avoid insolubility of the domain. |
==About this Structure== | ==About this Structure== | ||
| - | 1YC7 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Camelus_dromedarius Camelus dromedarius] with SO4 as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1YC7 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Camelus_dromedarius Camelus dromedarius] with <scene name='pdbligand=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1YC7 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: camel antibody]] | [[Category: camel antibody]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:03:49 2008'' |
Revision as of 14:03, 21 February 2008
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cAbAn33 VHH fragment against VSG
Overview
Heavy chain only antibodies of camelids bind their antigens with a single domain, the VHH, which acquired adaptations relative to classical VHs to function in the absence of a VL partner. Additional CDR loop conformations, outside the canonical loop structures of VHs, broaden the repertoire of the antigen-binding site. The combined effects of part of the CDR3 that folds over the "former" VL binding site and framework-2 mutations to more hydrophilic amino acids, enhance the solubility of VHH domains and prevent VL pairing. cAbAn33, a VHH domain specific for the carbohydrate moiety of the variant surface glycoprotein of trypanosomes, has a short CDR3 loop that does not cover the former VL binding site as well as a VH-specific Trp47 instead of the VHH-specific Gly47. Resurfacing its framework-2 region (mutations Tyr37Val, Glu44Gly and Arg45Leu) to mimic that of a human VH restores the VL binding capacity. In solution, the humanised VHH behaves as a soluble, monomeric entity, albeit with reduced thermodynamic stability and affinity for its antigen. Comparison of the crystal structures of cAbAn33 and its humanised derivative reveals steric hindrance exerted by VHH-specific residues Tyr37 and Arg45 that prevent the VL domain pairing, whereas Glu44 and Arg45 are key elements to avoid insolubility of the domain.
About this Structure
1YC7 is a Single protein structure of sequence from Camelus dromedarius with as ligand. Full crystallographic information is available from OCA.
Reference
Antigen binding and solubility effects upon the veneering of a camel VHH in framework-2 to mimic a VH., Conrath K, Vincke C, Stijlemans B, Schymkowitz J, Decanniere K, Wyns L, Muyldermans S, Loris R, J Mol Biol. 2005 Jul 1;350(1):112-25. PMID:15913651
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