Studying protein folding cooperativity with pressure perturbation

Abstract

protein. The C-terminal domain of the ribosomal protein L9 (CTL9) is a small globular protein. Pressure and temperature dependent NMR revealed significant deviations from two-state behavior for CTL9, with its hydrophobic core selectively destabilized by increasing temperature. Yet the I98A mutation in the core resulted in highly cooperative pressure unfolding. These observations indicate that local stability, as opposed to long-range interactions, determines folding cooperativity.