Research
General Goal:
The primary objective of the Eggers Research Laboratory is to understand the thermodynamic role of water in biochemistry. We believe that the classical approach for analyzing binding and conformational equilibria is flawed because there is no energetic consideration for the water molecules that are released to the bulk phase when two surfaces make direct contact. In essence, the classical equation (as found in most textbooks) represents an unbalanced reaction, leading to confusion and impeding progress on many issues related to solution chemistry. We have developed a new governing equation for binding equilibria in solution that accounts for the change in chemical potential of the unique subset of water molecules involved in the reaction. This contribution to the overall thermodynamics is referred to as the change in solvation free energy, ΔGS, and the sign and magnitude of this energy may be estimated experimentally by measuring the change in the equilibrium quotient, K, as a function of concentration. The derivation was first published in 2013 by Castellano and Eggers, with an expanded discussion in 2020 (Eggers, Fu, Ngo, Vuong, and Brotin). Please see the Publications tab for our most recent articles on this topic.
Governing Equation:
Possible Relation to Hofmeister Ion Effects:
One of the early motivating factors for pursuing this research direction was a desire to understand the mechanism by which secondary solutes alter the structure and stability of proteins. For example, we wanted to explain why some salt ions from the Hofmeister series are favorable for protein folding, whereas other ions are destabilizing. A recent paper in ACS Omega (2024) reveals how secondary solutes may alter binding equilibria by altering the average free energy of the water molecules that comprise the bulk phase, in addition to direct solute–reactant interactions. This rationale may also underly many observations related to the Hofmeister series and may yield new insights on the mode of action of chaotropes, crowding agents, and natural osmolytes. We urge other scientists to pursue these ideas by testing their favorite model reaction against the governing equation above.
