Salt Specific Interaction Between RepresentativeHofmeister Salts and Glycine

摘要

Traditionally,Hofmeister effect was understood on the basis of hydration abilities of ions.Recent studies found short-range structuring effects of ions on water which shifted the attention from ion-water interaction to ion-protein interaction.In this study,ATR-FTIR spectroscopy at different RH is used to study the effect of a representative Kosmotrope(MgSO4),Chaotrope(NH4NO3)and neutral(KCl)salt on glycine.The salting out,salting in and neutral effects of salts on glycine are found aligned with Hofmeister effect.Interestingly,direct interaction of kosmotrope anion(SO2-4)with the glycine is observed experimentally which validates the recent idea of ion-protein interaction.Further detailed studies will be needed for deeper insight.