(589d) How the Solvation of Flexible Solutes Influences Their Conformations

Under ambient conditions, globular proteins fold into well-defined “native” states, which are stabilized in part by a reduction in unfavorable protein-water interactions. Under a variety of conditions, such as lower temperatures, higher pressures, proximity to hydrophobic interfaces, and the presence of certain co-solutes, which modulate protein-water interactions, proteins can be unfolded or denatured resulting in a loss of their function. Using hydrophobic polymers as model globular proteins, here we study how the hydration environment of a polymer influences the thermodynamics of its collapse / folding transition. We find that near ambient conditions, typical hydrophobic macromolecules are situated at the edge of a collective collapse transition, making them particularly sensitive to perturbations such as the application of pressure or the presence of co-solutes.