Effects of the Protein Environment on the Structure and Energetics of Active Sites of Metalloenzymes. ONIOM Study of Methane Monooxygenase and Ribonucleotide Reductase
journal contributionposted on 18.12.2001, 00:00 by Maricel Torrent, Thom Vreven, Djamaladdin G. Musaev, Keiji Morokuma, Ödön Farkas, H. Bernhard Schlegel
As the first application of our recently developed ONIOM2(QM:MM) and ONIOM3(QM:QM:MM) codes to the metalloenzymes with a large number of protein residues, two members of the non-heme protein family, methane monooxygenause and ribonucleotide reductase, have been chosen. The “active-site + four α-helical fragments” model was adopted which includes about 1000 atoms from 62 residues around the Fe-centered spheres. Comparison of the active-site geometries of MMOH and R2 units optimized with this model with those obtained with the “active site only” (with only 39-46 atoms) model and the X-ray results clearly demonstrates the crucial role of the active site-protein interaction in the enzymatic activities.