Reorganisation Energy for Internal Electron Transfer in Multicopper Oxidases

0367566 - ÚOCHB 2012 RIV US eng J - Journal Article
Hu, L. H. - Farrokhnia, M. - Heimdal, J. - Shleev, S. - Rulíšek, Lubomír - Ryde, U.
Reorganisation Energy for Internal Electron Transfer in Multicopper Oxidases.
Journal of Physical Chemistry B. Roč. 115, č. 45 (2011), s. 13111-13126. ISSN 1520-6106. E-ISSN 1520-5207
R&D Projects: GA MŠMT LC512
Institutional research plan: CEZ:AV0Z40550506
Keywords : multi-copper oxidases * reorganization energy * QM/MM calculations
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 3.696, year: 2011

We have calculated the reorganization energy for the intramolecular electron transfer between the reduced type 1 copper site and the peroxy intermediate of the trinuclear cluster in the multicopper oxidase CueO. The calculations are performed at the combined quantum mechanics and molecular mechanics (QM/MM) level, based on molecular dynamics simulations with tailored potentials for the two copper sites. We obtain a reorganization energy of 91-133 kJ/mol, depending on the theoretical treatment. The two Cu sites contribute by 12 and 22 kJ/mol to this energy, whereas the solvent contribution is 34 kJ/mol. The rest comes from the protein, involving small contributions from many residues. We have also estimated the energy difference between the two electron-transfer states and show that the reduction of the peroxy intermediate is exergonic by 43-87 kJ/mol, depending on the theoretical method.
Permanent Link: http://hdl.handle.net/11104/0006681