Effects of pressure on the structure of metmyoglobin: Molecular dynamics predictions for pressure unfolding through a molten globule intermediate

We investigated the pathway for pressure unfolding of metmyoglobin using molecular dynamics (MD) for a range of pressures (0. 1 MPa to 1. 2 GPa) and a temperature of 300 K. We find that the unfolding of metmyoglobin proceeds via a two‐step mechanism native → molten globule intermediate → unfolded, where the molten globule forms at 700 MPa. The simulation describes qualitatively the experimental behavior of metmyoglobin under pressure. We find that unfolding of the alpha‐helices follows the sequence of migrating hydrogen bonds (i, i + 4) → (i, i + 2).