1. Speciation of Copper–Peptide Complexes in Water Solution Using DFTB and DFT Approaches: Case of the [Cu(HGGG)(Py)] Complex
- Author
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Vlasta Bonačić-Koutecký, Luca Bertini, Giuseppe Zampella, Luca De Gioia, Maurizio Bruschi, Roland Mitrić, Piercarlo Fantucci, Bruschi, M, Bertini, L, Bonačić Koutecký, V, DE GIOIA, L, Mitrić, R, Zampella, G, and Fantucci, P
- Subjects
CHIM/03 - CHIMICA GENERALE E INORGANICA ,Chemistry ,Water ,chemistry.chemical_element ,Molecular Dynamics Simulation ,Energy minimization ,Copper ,Relative stability ,Surfaces, Coatings and Films ,Solutions ,Molecular dynamics ,Cu-peptide complexes, SCC-DFTB, speciation, prion protein, bioinorganic chemistry ,Computational chemistry ,Genetic algorithm ,Organometallic Compounds ,Materials Chemistry ,Quantum Theory ,Water chemistry ,Physical and Theoretical Chemistry ,Peptides ,Parametrization - Abstract
The DFTB and DFT methods are applied to the study of different forms of the [Cu(HGGG)(Py)] complex in water, with the aim of identifying the most stable isomer. The DFTB calculations were possible thanks to a careful parametrization of the atom-atom repulsive energy terms for Cu-H, Cu-C, Cu-N, and Cu-O. The speciation process is carried out by computing different DFTB-steered molecular dynamics (SMD) trajectories, each of which ends in a well-defined different form. The last frame of each trajectory is subjected to geometry optimization at both DFTB and DFT levels, leading to a different isomer. From the corresponding energy values, a rank of relative stability of the isomers can be established. The computational protocol developed here is of general applicability to other metal-peptide systems and represents a new powerful tool for the study of speciation of metal-containing systems in water solution, particularly useful when the full characterization of the compound cannot be carried out on the basis of experimental results only.
- Published
- 2012
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