• Open Access

A Protein-Based Pentavalent Inhibitor of the Cholera Toxin B-Subunit

Authors

  • Dr. Thomas R. Branson,

    1. School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT (UK)
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  • Dr. Tom E. McAllister,

    1. School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT (UK)
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  • Jaime Garcia-Hartjes,

    1. Laboratory of Organic Chemistry, Wageningen University, Dreijenplein 8, 6703 HB Wageningen (The Netherlands)
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  • Dr. Martin A. Fascione,

    1. School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT (UK)
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  • Dr. James F. Ross,

    1. School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT (UK)
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  • Dr. Stuart L. Warriner,

    1. School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT (UK)
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  • Dr. Tom Wennekes,

    1. Laboratory of Organic Chemistry, Wageningen University, Dreijenplein 8, 6703 HB Wageningen (The Netherlands)
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  • Prof. Han Zuilhof,

    1. Laboratory of Organic Chemistry, Wageningen University, Dreijenplein 8, 6703 HB Wageningen (The Netherlands)
    2. Department of Chemical and Materials Engineering, King Abdulaziz University, Jeddah (Saudi-Arabia)
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  • Dr. W. Bruce Turnbull

    Corresponding author
    1. School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT (UK)
    • School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT (UK)===

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  • We thank Dr. G. A. Posthuma-Trumpie for her assistance with inhibition assays. This work was supported by the EPSRC (EP/G043302/1), the Wellcome Trust (089308/Z/09/Z; 094232/Z/10/Z), the Royal Society (UF090025), the Interreg IV program, a Netherlands Organization for Scientific Research VENI-grant (722.011.006), and COST Action CM1102.

Abstract

Protein toxins produced by bacteria are the cause of many life-threatening diarrheal diseases. Many of these toxins, including cholera toxin (CT), enter the cell by first binding to glycolipids in the cell membrane. Inhibiting these multivalent protein/carbohydrate interactions would prevent the toxin from entering cells and causing diarrhea. Here we demonstrate that the site-specific modification of a protein scaffold, which is perfectly matched in both size and valency to the target toxin, provides a convenient route to an effective multivalent inhibitor. The resulting pentavalent neoglycoprotein displays an inhibition potency (IC50) of 104 pM for the CT B-subunit (CTB), which is the most potent pentavalent inhibitor for this target reported thus far. Complexation of the inhibitor and CTB resulted in a protein heterodimer. This inhibition strategy can potentially be applied to many multivalent receptors and also opens up new possibilities for protein assembly strategies.

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