Organic Arsenicals As Efficient and Highly Specific Linkers for Protein/Peptide–Polymer Conjugation
| Autor: | John F. Quinn, Michael R. Whittaker, Phillip J. Hogg, Paul Wilson, Thomas P. Davis, Kristian Kempe, Sarah Mann, Athina Anastasaki, Angus P. R. Johnston, David M. Haddleton, Matthew R. Owen |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Calcitonin
Models Molecular Arsenites Stereochemistry Ether Peptide Biochemistry Arsenicals Catalysis Cell Line Polyethylene Glycols Polymerization Mice chemistry.chemical_compound Colloid and Surface Chemistry Salmon Animals Cysteine Sulfhydryl Compounds Bovine serum albumin Maleimide chemistry.chemical_classification biology Ethanedithiol General Chemistry Combinatorial chemistry Acrylates chemistry biology.protein Conjugate |
| Zdroj: | Journal of the American Chemical Society. 137:4215-4222 |
| ISSN: | 1520-5126 0002-7863 |
| Popis: | The entropy-driven affinity of trivalent (in)organic arsenicals for closely spaced dithiols has been exploited to develop a novel route to peptide/protein-polymer conjugation. A trivalent arsenous acid (As(III)) derivative (1) obtained from p-arsanilic acid (As(V)) was shown to readily undergo conjugation to the therapeutic peptide salmon calcitonin (sCT) via bridging of the Cys(1)-Cys(7) disulfide, which was verified by RP-HPLC and MALDI-ToF-MS. Conjugation was shown to proceed rapidly (t < 2 min) in situ and stoichiometrically through sequential reduction-conjugation protocols, therefore exhibiting conjugation efficiencies equivalent to those reported for the current leading disulfide-bond targeting strategies. Furthermore, using bovine serum albumin as a model protein, the trivalent organic arsenical 1 was found to demonstrate enhanced specificity for disulfide-bond bridging in the presence of free cysteine residues relative to established maleimide functional reagents. This specificity represents a shift toward potential orthogonality, by clearly distinguishing between the reactivity of mono- and disulfide-derived (vicinal or neighbors-through-space) dithiols. Finally, p-arsanilic acid was transformed into an initiator for aqueous single electron-transfer living radical polymerization, allowing the synthesis of hydrophilic arsenic-functional polymers which were shown to exhibit negligible cytotoxicity relative to a small molecule organic arsenical, and an unfunctionalized polymer control. Poly(poly[ethylene glycol] methyl ether acrylate) (PPEGA480, DPn = 10, Mn,NMR = 4900 g·mol(-1), Đ = 1.07) possessing a pentavalent arsenic acid (As(V)) α-chain end was transformed into trivalent As(III) post-polymerization via initial reduction by biological reducing agent glutathione (GSH), followed by binding of GSH. Conjugation of the resulting As(III)-functional polymer to sCT was realized within 35 min as indicated by RP-HPLC and verified later by thermodynamically driven release of sCT, from the conjugate, in the presence of strong chelating reagent ethanedithiol. |
| Databáze: | OpenAIRE |
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