Abstract - Combined QM/MM calculations of an activesite of Cytochrome P450cam have been performed, before and after a binding process of Cytochrome P450cam to Putidaredoxin. The calculations have been carried out for two coordination spheres of the heme active-site of Cytochrome P450cam, namely a 5-coordinated, and a 6coordinated system of this protein having a water molecule as a 6th ligand. An experimentally observed increase of a Fe-S stretching frequency after the binding process of Cytochrome P450cam to Putidaredoxin, has been reproduced in our calculations. The best agreement between the experiment increase and the theoretical increase of this vibrational frequency was found in our calculations for the 6-coordinated heme active-site.
Marek Freindorf, Yihan Shao, Jing Kong, Thomas R.