Naslov
A density functional theory study of the coordination modes of physiological bis(L-histidinato)copper(II): the importance of intermolecular interactions

Autori
Marković, Marijana ; Ramek, Michael ; Sabolović, Jasmina

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
1st International Caparica Christmas Conference on Translational Chemistry - IC3TC 2015 Book of Abstracts / Capelo, Jose L ; Lodeiro, Carlos - Caparica : Proteomass (Portugal), 2015, 60 (O 6A)-60

ISBN
978-989-99361-7-1

Skup
1st International Caparica Christmas Conference on Translational Chemistry

Mjesto i datum
Caparica, Portugal; Almada, Portugal, 07.12.2016. - 10.12.2016

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
copper; L-histidine; DFT; conformational analysis; Raman spectra

Sažetak
Purpose: Bis(amino acidato)copper(II) complexes, Cu(aa)2, are biologically important compounds as a part of the accessible physiological pool for transport and storage of the essential element copper.1 Bis(L-histidinato)copper(II), Cu(L-His)2, was determined as the predominant Cu(aa)2 in the blood. The essential role of Cu(L-His)2 in copper transport into the cell was crucial for its development as a therapeutic agent in the treatment of Menkes disease.1 During the past 40 years, the vast experimental physico-chemical characterisation studies of Cu(aa)2 in aqueous solutions mostly yielded the structural information on the first coordination sphere of Cu(II) only. Contrary, the complete information can be obtained by theoretical structure investigations using the density functional theory (DFT) method. Our recent DFT study of physiologically important Cu(L-His)2 was the first that clarified its structure in aqueous solution at physiological conditions.2 The main aim of the study was to contribute to the physico-chemical characterisation data necessary to discover new potential drugs. Namely, the interest in copper coordination complex research as antiproliferative agents has markedly increased in the last few years. Experimental description: In the physiological Cu(L-His)2 molecule, L-His can coordinate to Cu(II) in three modes: glycine-like, G, histamine-like, H, and imidazole-propionic acid-like, I. We investigated the relative stability of all possible coordination modes and conformations of isolated Cu(L-His)2, and several conformers surrounded with up to 22 H2O.2 The geometries and energies were calculated by the DFT/B3LYP method using the LanL2DZ basis set to which a set of polarisation and diffuse functions on heavy atoms except for copper was added. The IR and Raman spectra of four Cu(L-His)2·20H2O structures, with different Cu(II) coordination geometries, were calculated. Results: Among the 83 isolated conformers obtained, the most stable one had a trans-GG coordination. In the four Cu(L-His)2·20H2O systems, the lowest energy was estimated for a cis-HH conformer. The B3LYP dependence between the wavenumbers and Raman intensities for the cis-HH minimum revealed a very close resemblance with the experimental Raman spectrum.3 Thus, the calculations supported the experimental results with the information on the exact conformation and cis-configuration (there was a supposition in the literature that the HH coordination might be trans)3 of the prevailing species under physiological conditions. Conclusions: We concluded that the local arrangement of water molecules around Cu(L-His)2 and intermolecular interactions might influence the conformations and coordination modes. Key Words: Amino acids / Conformation analysis / Hydrogen bonds / Raman spectroscopy Acknowledgements: The project grant of the Croatian Science Foundation. Correspondence: Email: jasmina.sabolovic@imi.hr 1. P. Deschamps, P. P. Kulkarni, M. Gautam-Basak, B. Sarkar, Coord. Chem. Rev. 2005, 249, 895–909. 2. M. Marković, M. Ramek, J. Sabolović, Eur. J. Inorg. Chem. 2014, 198–212. 3. J. G. Mesu, T. Visser, F. Soulimani, E. E. van Faassen, P. de Peinder, A. M. Beale, B. M. Weckhuysen, Inorg. Chem. 2006, 45, 1960–1971.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija

Napomena
Sudjelovanje J. Sabolović s pozvanim usmenim izlaganjem na konferenciji dio je projekta Hrvatske zaklade za znanost broj IP-2014-09-3500

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