Počet záznamů: 1
Multi-scale modeling of electronic spectra of three aromatic amino acids: importance of conformational averaging and explicit solute-solvent interactions
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SYSNO ASEP 0433378 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název Multi-scale modeling of electronic spectra of three aromatic amino acids: importance of conformational averaging and explicit solute-solvent interactions Tvůrce(i) Štěpánek, Petr (UOCHB-X) RID
Bouř, Petr (UOCHB-X) RID, ORCIDCelkový počet autorů 2 Zdroj.dok. Physical Chemistry Chemical Physics. - : Royal Society of Chemistry - ISSN 1463-9076
Roč. 16, č. 38 (2014), s. 20639-20649Poč.str. 11 s. Jazyk dok. eng - angličtina Země vyd. GB - Velká Británie Klíč. slova magnetic circular dichroism ; density functional theory ; Raman optical activity Vědní obor RIV CF - Fyzikální chemie a teoretická chemie CEP GA13-03978S GA ČR - Grantová agentura ČR GAP208/11/0105 GA ČR - Grantová agentura ČR LH11033 GA MŠMT - Ministerstvo školství, mládeže a tělovýchovy Institucionální podpora UOCHB-X - RVO:61388963 UT WOS 000342072300044 EID SCOPUS 84920808680 DOI 10.1039/c4cp02668c Anotace Electronic transitions in the ultraviolet and visible spectral range can reveal a wealth of information about biomolecular geometry and interactions, such as those involved in protein folding. However, the modeling that provides the necessary link between spectral shapes and the structure is often difficult even for seemingly simple systems. To understand as to how conformational equilibria and solute-solvent interaction influence spectral intensities, we collected absorption (UV-vis), electronic circular dichroism (ECD), and magnetic circular dichroism (MCD) spectra of phenylalanine (Phe), tyrosine (Tyr) and tryptophan (Trp) zwitterions in aqueous solutions, and compared them with quantum-chemical simulations. These aromatic amino acids provide a relatively strong signal in the accessible wavelength range. At the same time, they allow for a relatively accurate modeling. Energies and intensities of spectral bands were reproduced by the time-dependent density functional theory (TD DFT). The solvent was approximated by a continuum as well as clusters containing solvent molecules from the first hydration sphere. The ECD signal was found to be strongly dependent on molecular conformation, and the dependence was much weaker in UV-vis and MCD spectra. All spectral intensities, however, were significantly affected by the solvent approximation; especially for ECD and MCD the usual polarizable continuum solvent model did not yield satisfactory spectral shapes. On the other hand, averaging of the clusters obtained from molecular dynamics simulations provided an unprecedented agreement with the experiment. Proper modeling of the interactions with the environment thus makes the information about the molecular structure, as obtained from the electronic spectra, more accurate and reliable. Pracoviště Ústav organické chemie a biochemie Kontakt asep@uochb.cas.cz ; Kateřina Šperková, Tel.: 232 002 584 ; Jana Procházková, Tel.: 220 183 418 Rok sběru 2015
Počet záznamů: 1