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).
Floriano
W B
WB
Materials and Process Simulation Center, Beckman Institute, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena 91125, USA.
Nascimento
M A
MA
Domont
G B
GB
Goddard
W A
WA
D000595:Amino Acid Sequence; D003198:Computer Simulation; D006860:Hydrogen Bonding; D008786:Metmyoglobin / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011312:Pressure; D011487:Protein Conformation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D016415:Sequence Alignment; D012997:Solvents; D013696:Temperature; D014364:Tryptophan / Q000737:chemistry
D012997:Solvents; D008786:Metmyoglobin; D014364:Tryptophan