18 research outputs found
Physiological roles of pyruvate ferredoxin oxidoreductase and pyruvate formate-lyase in Thermoanaerobacterium saccharolyticum JW/SL-YS485
Catalytic Cycle of Multicopper Oxidases Studied by Combined Quantum- and Molecular-Mechanical Free-Energy Perturbation Methods
We have used combined quantum mechanical and molecular mechanical free-energy perturbation
methods in combination with explicit solvent simulations to study the reaction mechanism of the
multicopper oxidases, in particular the regeneration of the reduced state from the native
intermediate. For 52 putative states of the trinuclear copper cluster, differing in the oxidation states
of the copper ions and the protonation states of water- and O2-derived ligands, we have studied
redox potentials, acidity constants, isomerisation reactions, as well as water- and O2 binding
reactions. Thereby, we can propose a full reaction mechanism of the multicopper oxidases with
atomic detail. We also show that the two copper sites in the protein communicate so that redox
potentials and acidity constants of one site are affected by up to 0.2 V or 3 pKa units by a change
in the oxidation state of the other site