STRUCTURE PREDICTION OF PHYSIOLOGICAL BIS(AMINOACIDATO)COPPER(II) IN AQUEOUS SOLUTION: THE (L-HISTIDINATO)(L-GLUTAMINATO)COPPER(II) SYSTEM (CROSBI ID 729856)
Prilog sa skupa u zborniku | sažetak izlaganja sa skupa | međunarodna recenzija
Podaci o odgovornosti
Sabolović, Jasmina ; Ramek, Michael ; Pejić, Jelena
projekt HrZZ IP-2004-09-3500
engleski
STRUCTURE PREDICTION OF PHYSIOLOGICAL BIS(AMINOACIDATO)COPPER(II) IN AQUEOUS SOLUTION: THE (L-HISTIDINATO)(L-GLUTAMINATO)COPPER(II) SYSTEM
Electrically neutral bis(aminoacidato)copper(II) [Cu(aa)2] coordination compounds are the physiological species of copper(II) amino acid compounds in blood plasma, preferentially bound with l-histidine (His) in bis(L- histidinato)copper(II), and ternary copper(II)–l- amino acid complexes containing His. These low- molecular-weight (LMW) compounds were suggested to be part (~0.2%) of an exchangeable Cu(II) pool in human blood plasma for transport, storage, and distribution in the body [1]. Generally, LMW Cu(II) coordination compounds strongly prefer a planar configuration in solution, with Cu(II) bound with four nearby donor atoms arranged approximately in a plane around the metal ion, with the possibility of one or two more axial donor atoms at a larger distance due to the Jahn- Teller effect. When a potentially tridentate amino acid forms a chelate with Cu(II), there are many possibilities of both axial and planar bonds. Generally, the experimental studies of the physiological Cu(aa)2 complexes did not determine their exact and complete structures in solutions. This computational study resolves that missing piece of information for (l-histidinato)(l- glutaminato)copper(ll) [Cu(His)(Gln)] by exploring the structural properties and energy landscapes using the density functional theory (DFT) with the B3LYP functional. Systematic conformational analysis of Cu(His)(Gln) with various combinations of the His and Gln in-plane binding modes and apical donor atoms in implicitly modeled aqueous surroundings using a polarizable continuum model located the low-energy conformers and coordination modes. The predicted lower-energy aqueous structures were verified by the DFT calculations of the g-factor and hyperfine coupling constant (HFCC) tensor of the 63Cu (ACu) and 14N (AN) centers for a quantitative comparison to experimental electron paramagnetic resonance (EPR) data. The EPR spectrum of Cu(His)(Gln) was obtained from a frozen solution of the copper(II)/l-His/l-Gln mixture in 1:1:1 molar ratio at pH 7 frozen solutions (at 80 K) [2]. The best reproduction of the experimental EPR data was obtained for the conformers with His and Gln in- plane binding via the histaminato and glycinato mode, respectively, in a cis configuration, and with His carboxylato oxygen atom at the apical position. The aim is to gain structural properties and information on effects of intra- and intermolecular interactions on the geometry and relative stability of physiologically important Cu(aa)2 as part of their physicochemical characterization for prospective pharmacological activity and use. Acknowledgment: This work was supported by the Croatian Science Foundation under the project IP- 2014-09-3500. [1] T. Kirsipuu, A. Zadorožnaja, J. Smirnova, M. Friedemann, T. Plitz, V. Tõugu, P. Palumaa, Sci. Rep. 20 (2020) 5686. [2] P. Deschamps, N. Zerrouk, T. Martens, M.-F. Charlot, J. J. Girerd, J. C. Chaumeil, A. Tomas, J. Trace Microprobe Tech. 21 (2003) 729–741.
Bioinorgranic ; Amino acids ; Structural properties ; Conformation analysis ; Density functional calculations ; EPR g tensor and hyperfine coupling
Pozvano izlaganje Jasmine Sabolović održano 04.07.2022., sekcija Invited Communications 1F
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Podaci o prilogu
Invited Communications 1F
2022.
objavljeno
Podaci o matičnoj publikaciji
Boyd, Russell
Vancouver: Chemical Institute of Canada
Podaci o skupu
12th Triennial Congress of the World Association of Theoretical and Computational Chemists
pozvano predavanje
03.07.2022-08.07.2022
Vancouver, Kanada