engleski

Quantum chemical study of bis(L- threoninato)copper(II) in the gas phase and aqueous solution

Bis(L-threoninato)copper(II), Cu(L-Thr)2, is part of the exchangeable pool of copper(II) in human blood plasma. One L-Thr can bind to Cu(II) via amino nitrogen (Nam), carboxylato oxygen (O), and hydroxy oxygen (Ohyd) atoms, in three coordination modes: 1. a glycine-like (via Nam and O), 2. an amino-hydroxy (via Nam and Ohyd), 3. a carboxy-hydroxy (via O and Ohyd), yielding six possible coordination modes in Cu(L-Thr)2. Visible absorption and circular dichroism measurements of Cu(L-Thr)2 in aqueous solution showed that at neutral pH both L-Thr ligands have a glycine-like coordination mode (Grenouillet et al., Biochim Biophys Acta, 322, 1973, 185). At pH ~ 9.4, a coordination via Nam and Ohyd atoms is formed (Noethig-Laslo et al., Monatsh Chem Chem Mon, 128, 1997, 1101). To examine the relative stabilities of coordination modes and conformations, we performed conformational analyses in the gas phase and aqueous solution by the quantum chemical DFT/B3LYP method. The glycine-like coordination turned out to be the most stable in both surroundings.

copper ; L-threonine ; conformational analysis ; QM ; DFT/B3LYP ; gas phase ; aqueous solution

Sudjelovanje Marijane Marković na skupu dio je projekta Hrvatske zaklade za znanost broj HRZZ-IP-2014-09-3500.