School of Chemistry Colloquium: Professor Bruce Gibb (Tulane University, USA) Interrogating how temperature and salts induce peptide unfolding

It is well understood that the graph of the free energy of unfolding of a globular protein with temperature is (approximately) parabolic. This ΔG(T) function is a negative parabola with a maximum; the temperature (Tmax) at which the protein is maximally folded, and either cooling or heating of a solution of the protein induces denaturation. There are still many open questions concerning the protein stability curve, and therefore an even poorer understanding of how protein stability is affected by the presence of salts (Hofmeister effects). Consequently, improvements in this area would be of immense benefit to all areas of science where handling proteins is key.
This seminar will describe work focused on: 1) building an understanding of how different structural elements — residue type, non-covalent interactions between residues, and secondary structure type — contribute to engender the unique parabolic ΔG(T) function of each protein, and; 2) understanding how anions interact with folded proteinaceous structure to affect stability. In both cases, our approach involves well-folded, β-hairpin peptides and information-rich 1H NMR spectroscopy. This combination allows a per-residue interrogation of unfolding induced by either temperature or salts, revealing a wealth of information which, when paired with structural and binding assessments, gives a more nuanced view of protein stability and Hofmeister effects.

This event is open to academic staff, post-doctoral researchers, PhD students and MSc students.