Multi-scale modeling of electronic spectra of three aromatic amino acids: importance of conformational averaging and explicit solute-solvent interactions

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F14%3A10288348" target="_blank" >RIV/00216208:11310/14:10288348 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/61388963:_____/14:00433378 RIV/00216208:11320/14:10288348

Výsledek na webu

<a href="http://pubs.rsc.org/en/content/articlepdf/2014/cp/c4cp02668c" target="_blank" >http://pubs.rsc.org/en/content/articlepdf/2014/cp/c4cp02668c</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/c4cp02668c" target="_blank" >10.1039/c4cp02668c</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Multi-scale modeling of electronic spectra of three aromatic amino acids: importance of conformational averaging and explicit solute-solvent interactions

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

Multi-scale modeling of electronic spectra of three aromatic amino acids: importance of conformational averaging and explicit solute-solvent interactions

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

<a href="/cs/project/GAP208%2F11%2F0105" target="_blank" >GAP208/11/0105: Rozšíření metod vibrační optické aktivity pro oblast biomolekul</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2014

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physical Chemistry Chemical Physics

ISSN

1463-9076

e-ISSN

—

Svazek periodika

16

Číslo periodika v rámci svazku

38

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

11

Strana od-do

20639-20649

Kód UT WoS článku

000342072300044

EID výsledku v databázi Scopus

—