Polyelectrolyte and anti-polyelectrolyte effects on chain conformations of polyzwitterions

Polyzwitterions are considered as model synthetic analogues of intrinsically disordered proteins. Based on this analogy, polyzwitterion chains in dilute aqueous solutions

are expected to attain either globular (i.e., molten, compact) or random coil conforma-

tions. Addition of salt is expected to open these conformations either due to screen-

ing of dipole-dipole interactions or because of ion-binding to zwitterion groups. Such an effect of salt on chain conformations is called an anti-polyelectrolyte effect. In this talk, I will present our work related to characterizing the anti-polyelectrolyte effect for a polysulfobetaine using dynamic light scattering, small-angle X-ray scattering, ab initio molecular dynamics, and a uniform expansion model. Also, we have discovered a salt concentration range over which the polyelectrolyte effect is observed leading to a shrinkage of polyzwitterionic chains. Implications of these findings on preparing coacervates based on polyzwitterions will be discussed.