Naslov
Quantum chemical conformational analyses unveil conformational flexibility of physiological (L-histidinato)(L-threoninato)copper(II) in aqueous solution

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

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

Izvornik
11th Triennial Congress of the World Association of Theoretical and Computational Chemists -WATOC 2017 - BOOK OF ABSTRACTS WITH SCIENTIFIC PROGRAM / Ochsenfeld, Christian - München : Ludwig-Maximilians-Universität (LMU) München, 2017, PO2-34

Skup
11th Triennial Congress of the World Association of Theoretical and Computational Chemists -WATOC 2017

Mjesto i datum
München, Njemačka, 27.08.2017. - 01.09.2017

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
copper, amino acids, DFT, B3LYP, PCM, conformational analysis

Sažetak
By now experimental studies for physiological ternary (L-histidinato)(Lthreoninato) copper(II) complex in solutions did not report any firm structural information [1, 2]. To complement experimental findings we performed conformational analyses for the ternary complex in the gas phase and in an implicitly modeled aqueous medium using the density functional theory (DFT) functional B3LYP [3]. 1728 initial structures, which cover the conformational space of the complex in three copper(II) coordination modes with trans- and cis-configuration, were used for geometry optimizations. The effects of intermolecular interactions on the complex properties are examined. Different energy landscapes in the gas phase and aqueous solution are obtained with much more possible aqueous conformers than vacuum conformers. Less strained structures are detected in aqueous solution than in the gas phase. While the trans conformers in glycine-like coordination are the most stable in vacuum, conformers in all coordination modes are predicted within 15 kJ mol-1 in aqueous solution. The diversity of lowest-energy aqueous geometries with or without the intra- and inter-residual hydrogen bonds, and comparisons with the previously studied parent binary complexes bis(L-histidinato)copper(II) [4] and bis(L-threoninato)copper(II) [5] reveal a pronounced conformational flexibility of the title complex in aqueous solution. The flexibility explains previous experimental findings [1, 2] on the lack of inter-residual strain and the abundance of the ternary over the parent complexes determined in aqueous solutions at physiological pH values. Acknowledgment: This work has been supported by the Croatian Science Foundation under the project IP-2014-09-3500. [1] H. C. Freeman, R.-P. Martin, J. Biol. Chem. 24, 4823 (1969). [2] O. Yamauchi, T. Sakurai, A. Nakahara, J. Am. Chem. Soc. 101, 4164 (1979). [3] M. Ramek, M. Marković, C. Loher, J. Sabolović, Polyhedron (submitted). [4] M. Marković, M. Ramek, J. Sabolović, Eur. J. Inorg. Chem. 198 (2014). [5] M. Marković, M. Ramek, C. Loher, J. Sabolović, Inorg. Chem. 55, 7694 (2016).

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija

POVEZANOST RADA