Electron Transfer in the P450cam/PDX Complex. The QM/MM e-Pathway

FRANK WALLRAPP; DIEGO MASONE; VICTOR GUALLAR

JOURNAL OF PHYSICAL CHEMISTRY A

AMER CHEMICAL SOC

Año: 2008 vol. 112 p. 12989 - 12994

1089-5639

Electron transfer processes are simple but crucial reactions in biochemistry, being one of the main steps in almost all enzymatic cycles. Obtaining an atomic description of the transfer pathway is a difficult task, at both the experimental and theoretical levels. Here we combine protein-protein docking algorithms, protein structure prediction methodologies and mixed quantum mechanics/molecular mechanics techniques to map the electron transfer pathway between cytochrome P450 camphor and its redox partner, putidaredoxin. Although the mechanism of interaction and electron transfer for this redox couple has been under investigation for over 30 years, the exact mechanism and electron transfer pathway has not been fully understood, yet. Our results report the first ab initio quantum chemistry description of the electron migration. The obtained electron transfer pathway indicates the key role of Arg112 of P450 and Asp38 of PDX and the existence of slightly different electron transfer pathways for different protein-protein complexes.