Reductive cleavage of the O-O bond in multicopper oxidases: a QM/MM and QM study

0360794 - ÚOCHB 2012 RIV GB eng J - Journal Article
Srnec, Martin - Ryde, U. - Rulíšek, Lubomír
Reductive cleavage of the O-O bond in multicopper oxidases: a QM/MM and QM study.
Chemical Society. Faraday Discussions. Roč. 148, - (2011), s. 41-53. ISSN 0301-7249
R&D Projects: GA MŠMT LC512
Institutional research plan: CEZ:AV0Z40550506
Keywords : multi-copper oxidases * QM/MM calculations * reaction mechanism * O2 bond cleavage
Subject RIV: CF - Physical ; Theoretical Chemistry

The key step in the reaction mechanism of multicopper oxidases (MCOs) -- the cleavage of the O--O bond in O2 -- has been investigated using combined quantum mechanical and molecular mechanical (QM/MM) methods. Our best estimate of the activation barrier is (delta)G = 60--65 kJ.mol-1, in good agreement with the experimental barrier of /~55 kJ.mol-1, which can be inferred from the experimental rate constant of k > 350 s-1. It has also been shown that the reaction involves protonation of the O2 moiety before bond cleavage. The proton likely comes from a nearby carboxylate residue which was recently suggested by the experiments.
Permanent Link: http://hdl.handle.net/11104/0198261