Cation-amino acid interactions: Implications for protein destabilization.

The mechanism for protein stabilization or destabilization has long been an open quest. In the present study, we have studied the interactions between amino acids and guanidinium (Gdm)/ammonium (NH) ions by using low field nuclear magnetic resonance (LF-NMR), where Gdm and NH are denaturant and stabilizer for proteins, respectively. It shows that Gdm favors to bind to the thiol group or the hydroxyl group on the side chain but weakly interacts with the α-carboxyl group.

Dynamical heterogeneity in the gelation process of a polymer solution with a lower critical solution temperature.

The gelation of a hydrophobically modified hyaluronic acid aqueous solution which shows a lower critical solution temperature of about 25 °C was investigated by multi-particle tracking microrheology. The linear viscoelasticity of the gelling system is converted from the microrheological data. The critical gelling temperature T = 36.