Cytochrome c: the effect of temperature and pressure from molecular dynamics simulations

Cytochrome c has been extensively investigated due to its role in the process of electron transfer in the mitochondrial system. The effect of temperature and pressure on horse cytochrome c was investigated using normal mode analysis and Molecular Dynamics simulations. The conformational space of the molecule and the anharmonic component of oscillations were obtained further by molecular dynamics simulations for 1.5 ns in solvent environment. The simulated root means square fluctuations, radii of gyration, hydrogen bond arrangements and atomic packing densities reveal that the protein remains compact for the duration of the simulation; high temperature induced partial unfolding at surface regions was observed. The covalent bonding arrangement of the Fe (heme) was investigated during the simulation. These results provide insight into the stability of electron transport by cytochrome c under various pressures and temperatures and provide the regions that could be mutated to enhance the stability and electron transfer properties of the protein. (C) 2004 Elsevier Ltd. All rights reserved.