Understanding CH-Stretching Raman Optical Activity in Ala-Ala Dipeptides
Identifikátory výsledku
Kód výsledku v IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388963%3A_____%2F20%3A00521859" target="_blank" >RIV/61388963:_____/20:00521859 - isvavai.cz</a>
Nalezeny alternativní kódy
RIV/61989592:15310/20:73601074
Výsledek na webu
<a href="https://pubs.acs.org/doi/10.1021/acs.jpca.9b10557" target="_blank" >https://pubs.acs.org/doi/10.1021/acs.jpca.9b10557</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1021/acs.jpca.9b10557" target="_blank" >10.1021/acs.jpca.9b10557</a>
Alternativní jazyky
Jazyk výsledku
angličtina
Název v původním jazyce
Understanding CH-Stretching Raman Optical Activity in Ala-Ala Dipeptides
Popis výsledku v původním jazyce
Raman optical activity (ROA) becomes a standard method to monitor peptide conformation. However, the signal in the CH-stretching region is particularly difficult to measure and interpret. In order to understand the structural information contained in this part of the spectrum, data obtained on a custom-made ROA spectrometer have been analyzed for the model Ala-Ala molecule, with the help of molecular dynamics (MD) and density functional theory computations. The Ala-Ala enantiomers provided the „mirror image“ spectra, which proves that the signal can be reliably measured, in spite of a rather low ROA/Raman intensity ratio (∼2 × 10-5). The theoretical modeling indicated that the most intense ROA bands can be attributed to locally asymmetric CH3 and αCH vibrations, whereas symmetric methyl CH-stretching modes contribute less. A simplified model made it possible to estimate the contribution of local chirality of the two alanine residues to the resultant ROA pattern. In spite of a significant frequency shift (over 100 cm-1) because of the anharmonic corrections, the harmonic level was able to explain the main spectral features. The anharmonic corrections were treated by second-order perturbation and limited vibrational configuration interaction procedures. This allowed for assignment of some weaker spectral features because of the combination and overtone vibrations. The results show that the peptide CH-stretching ROA signal contains rich structural information, reflecting also the peptide environment. The experimental data, however, need to be deciphered by relatively complex and time-consuming spectral simulations.
Název v anglickém jazyce
Understanding CH-Stretching Raman Optical Activity in Ala-Ala Dipeptides
Popis výsledku anglicky
Raman optical activity (ROA) becomes a standard method to monitor peptide conformation. However, the signal in the CH-stretching region is particularly difficult to measure and interpret. In order to understand the structural information contained in this part of the spectrum, data obtained on a custom-made ROA spectrometer have been analyzed for the model Ala-Ala molecule, with the help of molecular dynamics (MD) and density functional theory computations. The Ala-Ala enantiomers provided the „mirror image“ spectra, which proves that the signal can be reliably measured, in spite of a rather low ROA/Raman intensity ratio (∼2 × 10-5). The theoretical modeling indicated that the most intense ROA bands can be attributed to locally asymmetric CH3 and αCH vibrations, whereas symmetric methyl CH-stretching modes contribute less. A simplified model made it possible to estimate the contribution of local chirality of the two alanine residues to the resultant ROA pattern. In spite of a significant frequency shift (over 100 cm-1) because of the anharmonic corrections, the harmonic level was able to explain the main spectral features. The anharmonic corrections were treated by second-order perturbation and limited vibrational configuration interaction procedures. This allowed for assignment of some weaker spectral features because of the combination and overtone vibrations. The results show that the peptide CH-stretching ROA signal contains rich structural information, reflecting also the peptide environment. The experimental data, however, need to be deciphered by relatively complex and time-consuming spectral simulations.
Klasifikace
Druh
J<sub>imp</sub> - Článek v periodiku v databázi Web of Science
CEP obor
—
OECD FORD obor
10403 - Physical chemistry
Návaznosti výsledku
Projekt
Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.
Návaznosti
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Ostatní
Rok uplatnění
2020
Kód důvěrnosti údajů
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Údaje specifické pro druh výsledku
Název periodika
Journal of Physical Chemistry A
ISSN
1089-5639
e-ISSN
—
Svazek periodika
124
Číslo periodika v rámci svazku
4
Stát vydavatele periodika
US - Spojené státy americké
Počet stran výsledku
10
Strana od-do
674-683
Kód UT WoS článku
000510531200009
EID výsledku v databázi Scopus
2-s2.0-85078693085