Density functional study of the heme moiety of cytochrome c

摘要: A model of cytochrome c (Cyt-c) including the porphyrin ring, a methionine residue (Met), and imidazole ring histidine (His), latter two being situated above below iron (Fe) atom was studied using Density Functional Theory (DFT). The geometries Cyt-c complex with Fe in different charge states were fully optimized, i.e., singlet triplet for doublet quartet Fe3+. B3LYP method DFT along 3-21G* basis set C, H, N, O atoms Lanl2dz used. We found that Fe3+, spin state is ground lies slightly it. geometry similar to states. However, has conformations when zero (singlet, states) relative situation +3 charges (doublet, states). Met chain folded instead remaining extended going from or folding stabilized by an intramolecular CH..O hydrogen bond. optimized geometrical parameters are usually satisfactory agreement those observed experimentally. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem,