REVIEW: High pressure NMR study of proteins - seeking roots for function, evolution, disease and food applications

NMR experiments at variable pressure reveal a wide range of conformation of a globular protein spanning from within the folded ensemble to the fully unfolded ensemble, herewith collectively called ohigh-energy conformerso. The observation of ohigh-energy conformerso in a wide variety of globular proteins has led to the ovolume theoremo: the partial molar volume of a protein decreases with the decrease in its conformational order. Since ohigh-energy conformerso are intrinsically more reactive than the basic folded conformer, they could play decisive roles in all phenomena of proteins, namely function, environmental adaptation and misfolding. Based on the information on high-energy conformers and the rules on their partial volume in its monomeric state and amyloidosis, one may have a general view on what is happening on proteins under pressure. Moreover, one may even choose a high-energy conformer of a protein with pressure as variable for a particular purpose. Bridging ohigh-energy conformerso to macroscopic pressure effects could be a key to success in pressure application to biology, medicine, food technology and industry in the near future.