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A. V. Rogov, B. L. Grigorenko, A. V. Bochenkova, A. A. Granovskii, A. V. Nemukhin
The role of
magnesium in the hydrolysis reaction of triphosphates in aqueous solution:
quantum mechanical – molecular mechanical simulations
Abstract
The
mechanism of the hydrolysis reaction of the unprotonated methyl triphosphate
(MTP) ester resulting in the methyl diphosphate (MDP) and inorganic phosphate
(Pi) in water clusters in presence and absence of magnesium cation has been
modeled. The effective fragment potential based quantum mechanical – molecular
mechanical (QM/MM) approach has been applied in the simulations. Density
functional theory (B3LYP) approximation has been used for calculations of
energies and energy derivatives in the quantum subsystem (MTP, reacting water molecules
and Mg2+) while water-water interactions have been described with
the TIP3P model potential. It is shown that the minimum energy path for the
reaction MTP + H2O ®
MDP + Pi is consistent with the two-step dissociative-type process in the
absence of Mg2+, and the single-step transformation in the presence
of Mg2+.
Copyright (C) Chemistry Dept., Moscow State University, 2002
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