Trifluoroethanol-induced beta -> alpha transition in beta-lactoglobulin: hydration and cosolvent binding studied by 2H, 17O, and 19F magnetic relaxation dispersion.

摘要: Alcohols, such as 2,2,2-trifluoroethanol (TFE), have been shown to induce a cooperative transition an open helical structure in many proteins, but the underlying molecular mechanism has not identified. Here, we employ technique of magnetic relaxation dispersion (MRD) study TFE-induced β → α β-lactoglobulin at pH 2.4. Unlike traditional techniques that focus on protein secondary structure, MRD method directly monitors solvent, providing quantitative information about preferential solvation and solvent penetration overall size structural integrity protein. In this multinuclear study, use 2H 17O resonances examine hydration 19F resonance TFE. The transformation from native state via intermediate 300 K is found be accompanied by progressive expansion loss specific long-lived sites. observation dispersions st...