Figure 9.

Combining subdenaturing concentrations of GuHCl with HHP allowed the characterization of population-weighted average states of p53C. The ensemble of native states (a) is converted to a population of states containing expanded volumes (ΔV = −106 ml/mol) with intermediate levels of hydrophobic exposure (b). Slightly increasing GuHCl leads to a volume retraction (ΔV = −67 ml/mol) and additional hydrophobic exposure (c). In these states, the local Trp probe is partially protected before full exposure. The use of pressures higher than 2.7 kbar leads p53C to an irreversible dead-end aggregation route (Agg). *, obtained through extrapolation to the data values at 100% unfolding. d, representation of the marginal unfolding cooperativity of the p53C ensemble of conformers upon small additions of GuHCl.