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

Abstract

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 “high-energy conformers”. The observation of “high-energy conformers” in a wide variety of globular proteins has led to the “volume theorem”: the partial molar volume of a protein decreases with the decrease in its conformational order. Since “high-energy conformers” 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 “high-energy conformers” to macroscopic pressure effects could be a key to success in pressure application to biology, medicine, food technology and industry in the near future.

Keywords:

• high pressure NMR
• high-energy conformers
• protein function
• environmental adaptation
• amyloid formation
• food applications

Acknowledgements

This work has been supported by the Academic Frontier Program 07F010 of the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT) and partly by the Development of Technology for Promoting Food Quality Program of the Niigata Industrial Creation Organization.