Understanding CH-Stretching Raman Optical Activity in Ala-Ala Dipeptides
The result's identifiers
Result code in 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>
Alternative codes found
RIV/61989592:15310/20:73601074
Result on the web
<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>
Alternative languages
Result language
angličtina
Original language name
Understanding CH-Stretching Raman Optical Activity in Ala-Ala Dipeptides
Original language description
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.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10403 - Physical chemistry
Result continuities
Project
Result was created during the realization of more than one project. More information in the Projects tab.
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2020
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Journal of Physical Chemistry A
ISSN
1089-5639
e-ISSN
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Volume of the periodical
124
Issue of the periodical within the volume
4
Country of publishing house
US - UNITED STATES
Number of pages
10
Pages from-to
674-683
UT code for WoS article
000510531200009
EID of the result in the Scopus database
2-s2.0-85078693085