Effect of pressure on the conformation of proteins. A molecular dynamics simulation of lysozyme

The effect of pressure on the structure and mobility of lysozyme was studied by molecular dynamics computer simulation at 1 and 3 kbar (1 atm = 1.01325 bar = 101.325 kPa). The results have good agreement with the available experimental data, allowing the analysis of other features of the effect of pressure on the protein solution. The studies of mobility show that although the general mobility is restricted under pressure this is not true for some particular residues. From the analysis of secondary structure along the trajectories it is observed that the conformation under pressure is more stable, suggesting that pressure acts as a ‘conformer selector’ on the protein. The difference in solvent-accessed surface (SAS) with pressure shows a clear inversion of the hydrophilic/hydrophobic SAS ratio, which consequently shows that the hydrophobic interaction is considerably weaker under high hydrostatic pressure conditions.