Reversible changes of the wheat gamma 46 gliadin conformation submitted tohigh pressures and temperatures

The structure of the wheat gamma 46 gliadin was investigated, in aqueous so lutions, under high pressure or temperature by the use of ultraviolet and f luorescence spectroscopic techniques. We found that high pressure (above 40 0 MPa) induces a change in the protein conformation that results in a decre ase of the polarity of the environment of aromatic amino acids. This new co nformation was able to bind the hydrophobic probe, 8-anilino-1-naphtalene-s ulfonic acid (ANS), indicating an increase in the gliadin surface hydrophob icity. Thermodynamic parameters of this conformational change were measured and infrared spectroscopy studies were used to probe the potential seconda ry structure modifications. The high stability of gamma 46 gliadin could be related to its elastic character, as the observed changes were always foun d to be reversible.