1llr: Difference between revisions
New page: left|200px<br /><applet load="1llr" size="450" color="white" frame="true" align="right" spinBox="true" caption="1llr, resolution 1.460Å" /> '''CHOLERA TOXIN B-PEN... |
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[[Image:1llr.jpg|left|200px]]<br /><applet load="1llr" size=" | [[Image:1llr.jpg|left|200px]]<br /><applet load="1llr" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1llr, resolution 1.460Å" /> | caption="1llr, resolution 1.460Å" /> | ||
'''CHOLERA TOXIN B-PENTAMER WITH LIGAND BMSC-0012'''<br /> | '''CHOLERA TOXIN B-PENTAMER WITH LIGAND BMSC-0012'''<br /> | ||
==Overview== | ==Overview== | ||
Multivalent ligand design constitutes an attractive avenue to the | Multivalent ligand design constitutes an attractive avenue to the inhibition of receptor recognition and other biological events mediated by oligomeric proteins with multiple binding sites. One example is the design of multivalent receptor blockers targeting members of the AB(5) bacterial toxin family. We report here the synthesis and characterization of a pentavalent inhibitor for cholera toxin and Escherichia coli heat-labile enterotoxin. This inhibitor is an advance over the symmetric pentacyclen-derived inhibitor described in our earlier work in that it presents five copies of m-nitrophenyl-alpha-D-galactoside (MNPG) rather than five copies of beta-D-galactose. The approximately 100-fold higher single-site affinity of MNPG for the toxin receptor binding site relative to galactose is found to yield a proportionate increase in the affinity and IC50 measured for the respective pentavalent constructs. We show by dynamic light scattering that inhibition of receptor binding by the pentavalent inhibitor is due to 1:1 inhibitor:toxin association rather than to inhibitor-mediated aggregation. This 1:1 association is in complete agreement with a 1.46 A resolution crystal structure of the pentavalent inhibitor:toxin complex, which shows that the favorable single-site binding interactions of MNPG are retained by the five arms of the 5256 Da pentavalent MNPG-based inhibitor and that the initial segment of the linking groups interacts with the surface of the toxin B pentamer. | ||
==About this Structure== | ==About this Structure== | ||
1LLR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Vibrio_cholerae Vibrio cholerae] with FNG as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | 1LLR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Vibrio_cholerae Vibrio cholerae] with <scene name='pdbligand=FNG:'>FNG</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LLR OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Vibrio cholerae]] | [[Category: Vibrio cholerae]] | ||
[[Category: Hol, W | [[Category: Hol, W G.J.]] | ||
[[Category: Merritt, E | [[Category: Merritt, E A.]] | ||
[[Category: FNG]] | [[Category: FNG]] | ||
[[Category: b-pentamer]] | [[Category: b-pentamer]] | ||
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[[Category: receptor]] | [[Category: receptor]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:46:05 2008'' | ||
Revision as of 14:46, 21 February 2008
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CHOLERA TOXIN B-PENTAMER WITH LIGAND BMSC-0012
OverviewOverview
Multivalent ligand design constitutes an attractive avenue to the inhibition of receptor recognition and other biological events mediated by oligomeric proteins with multiple binding sites. One example is the design of multivalent receptor blockers targeting members of the AB(5) bacterial toxin family. We report here the synthesis and characterization of a pentavalent inhibitor for cholera toxin and Escherichia coli heat-labile enterotoxin. This inhibitor is an advance over the symmetric pentacyclen-derived inhibitor described in our earlier work in that it presents five copies of m-nitrophenyl-alpha-D-galactoside (MNPG) rather than five copies of beta-D-galactose. The approximately 100-fold higher single-site affinity of MNPG for the toxin receptor binding site relative to galactose is found to yield a proportionate increase in the affinity and IC50 measured for the respective pentavalent constructs. We show by dynamic light scattering that inhibition of receptor binding by the pentavalent inhibitor is due to 1:1 inhibitor:toxin association rather than to inhibitor-mediated aggregation. This 1:1 association is in complete agreement with a 1.46 A resolution crystal structure of the pentavalent inhibitor:toxin complex, which shows that the favorable single-site binding interactions of MNPG are retained by the five arms of the 5256 Da pentavalent MNPG-based inhibitor and that the initial segment of the linking groups interacts with the surface of the toxin B pentamer.
About this StructureAbout this Structure
1LLR is a Single protein structure of sequence from Vibrio cholerae with as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Characterization and crystal structure of a high-affinity pentavalent receptor-binding inhibitor for cholera toxin and E. coli heat-labile enterotoxin., Merritt EA, Zhang Z, Pickens JC, Ahn M, Hol WG, Fan E, J Am Chem Soc. 2002 Jul 31;124(30):8818-24. PMID:12137534
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