Aqueous RAFT Synthesis of Low Molecular Weight Anionic Polymers for Determination of Structure/Binding Interactions with Gliadin

• Published in: Macromolecular bioscience Vol. 20; no. 8; pp. e2000125 - n/a
• Main Authors: Bristol, Ashleigh N., Carpenter, Brooke P., Davis, Ashley N., Kemp, Lisa K., Rangachari, Vijayaraghavan, Karim, Shahid, Morgan, Sarah E.
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01-08-2020
• Subjects: Acrylamide; Addition polymerization; anionic polymers; aqueous reversible addition fragmentation chain transfer; Autoimmune diseases; Celiac disease; Chain transfer; Chemical synthesis; Circular dichroism; Dichroism; eliac disease; Epitopes; Fluorescence; Fluorescence spectroscopy; Gliadin; Gluten; Hydrophobicity; Inflammation; Inflammatory response; Light scattering; Liquid chromatography; Low molecular weights; Molecular weight; non‐covalent binding; Photon correlation spectroscopy; Polyacrylamide; Polyelectrolytes; Polymer blends; Polymers; Protein structure; Scattering; Secondary structure; Sodium; Sulfonic acid; Zeta potential; eliac disease; aqueous reversible addition fragmentation chain transfer; anionic polymers; non-covalent binding; gliadin
• DOI: 10.1002/mabi.202000125
• EISSN: 1616-5195
• ISSN: 1616-5187

Gliadin, a component of gluten and a known epitope, is implicated in celiac disease (CeD) and results in an inflammatory response in CeD patients when consumed. Acrylamide‐based polyelectrolytes are employed as models to determine the effect of molecular weight and pendent group on non‐covalent interaction modes with gliadin in vitro. Poly(sodium 2‐acrylamido‐2‐methylpropane sulfonate) and poly(sodium 3‐methylpropyl‐3‐butanoate) are synthesized via aqueous reversible addition fragmentation chain transfer (aRAFT) polymerization and characterized by gel permeation chromatography‐multiangle laser light scattering. The polymer/gliadin blends are examined via circular dichroism, zeta potential measurements, 8‐anilinonaphthalene‐1‐sulfonic acid fluorescence spectroscopy, and dynamic light scattering. Acrylamide polymers containing strong anionic pendent groups have a profound effect on gliadin secondary structure and solution behavior below the isoelectric point, while polymers containing hydrophobic character only have a minor impact. The polymers have little effect on gliadin secondary structure and solution behavior at the isoelectric point.
Low molecular weight and low dispersity polyelectrolytes with sulfonate and carboxylate pendent groups, synthesized via reversible addition fragmentation chain transfer display structure‐ and pH‐dependent binding behavior with gliadin. At low pH, both systems alter gliadin secondary structure, with sulfonate functionality displaying the larger effect, while at neutral pH no binding is observed
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