| Based on published experimental data, an increase in binding affinity (−2.2 kcal/mol) exists for myoglobin (Mb) and carbon monoxide (CO) ligand when leucine occupies the 64th position (H64L) instead of wild type histidine. Molecular dynamics calculation of both wild type and H64L carbonmonoxy Mb were carried out at 300 K with explicit water solvent using the AMBER suite of programs. Estimates of the free energy difference between the two myoglobins was formed as the difference in energy as calculated by molecular dynamics. The resulting force field trajectories show the CO complex of H64L mutant to be 4.1 ± 0.8 kcal/mole less stable that the wild type. |
