Supramolecular chiral self-assembly and supercoiling behavior of carrageenans at varying salt conditions

Abstract

The self-assembly of anionic kappa and iota carrageenan polysaccharides in the presence of NaCl, KCl and CaCl₂ is studied by high-resolution atomic force microscopy (AFM). A hierarchical supramolecular chirality amplification over various length scales is observed upon the addition of KCl, whereas in the presence of NaCl and CaCl₂ the chains undergo solely a coil–helix transition with stiff kappa carrageenan and more flexible iota carrageenan helical conformations.