The fundamental influence of interfacial water on the macromolecules of biological systems can be modified by adding neutral salts to the solution (Hofmeister effect (HE)). Despite the widespread use of HE in colloid chemistry, preparative biochemistry and biotechnology, interpretation of the effects has remained a matter of debate. Recently, we published a theoretical grounding of the effects based on the salt dependence of solute-water interfacial tension. It was shown that the relation between the interfacial tension and protein structural stability is directly linked to protein conformational fluctuations. A methodological implication of the results is that HE is expected to change the reactions accompanying major conformational changes that involve water-exposed surface area changes of macromolecules and supramolecular assemblies.

The aim of our project is to utilize HE as research tool to reveal the role of interfacial water structure in protein structure, protein-protein and protein-ligand interactions. Two main topics are involved. The first is the influence of the Hofmeister active ions on the structure of intrinsically disordered proteins, among them those related to neurodegenarative diseases. The other topic is the biological consequences of the Hofmeister effect, regarding the hydration properties of residues with charged side chains.

Násztor Z, Dér A, Bogár F: Ion-induced alterations of the local hydration environment elucidate Hofmeister effect in a simple classical model of Trp-cage miniprotein JOURNAL OF MOLECULAR MODELING 23:(10) 298 (2017)

Násztor Z, Bogár F, Dér A The interfacial tension concept, as revealed by fluctuations CURRENT OPINION IN COLLOID & INTERFACE SCIENCE 23: 29-40 (2016).

Bogár F, Bartha F, Násztor Z, Fábian L, Leitgeb B, Dér A: On the Hofmeister Effect: Fluctuations at the Protein-Water Interface and the Surface Tension. JOURNAL OF PHYSICAL CHEMISTRY B 118:(29) 8496-8504 (2014).