Intense chiral signal from α-helical poly-L-alanine observed in low-frequency Raman optical activity

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388963%3A_____%2F21%3A00549139" target="_blank" >RIV/61388963:_____/21:00549139 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1039/D1CP04401J" target="_blank" >https://doi.org/10.1039/D1CP04401J</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/D1CP04401J" target="_blank" >10.1039/D1CP04401J</a>

Result language

angličtina

Original language name

Intense chiral signal from α-helical poly-L-alanine observed in low-frequency Raman optical activity

Original language description

Raman optical activity (ROA) spectral features reliably indicate the structure of peptides and proteins, but the signal is often weak. However, we observed significantly enhanced low-frequency bands for α-helical poly-L-alanine (PLA) in solution. The biggest ROA signal at ∼100 cm−1 is about 10 times stronger than higher-frequency bands described previously, which facilitates the detection. The low-frequency bands of PLA were compared to those of α-helical proteins. For PLA, density functional simulations well reproduced the experimental spectra and revealed that about 12 alanine residues within two turns of the α-helix generate the strong ROA band. Averaging based on molecular dynamics (MD) provided an even more realistic spectrum compared to the static model. The low-frequency bands could be largely related to a collective motion of the α-helical backbone, partially modulated by the solvent. Helical and intermolecular vibrational coordinates have been introduced and the helical unwinding modes were assigned to the strongest ROA signal at 101–128 cm−1. Further analysis indicated that the helically arranged amide and methyl groups are important for the strong chiral signal of PLA, while the local chiral centers CαH contribute in a minor way only. The strong low-frequency ROA can thus provide precious information about the motions of the peptide backbone and facilitate future protein studies.

Czech name

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Czech description

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Type

J_imp - 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

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

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

Publication year

2021

Confidentiality

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

Name of the periodical

Physical Chemistry Chemical Physics

ISSN

1463-9076

e-ISSN

1463-9084

Volume of the periodical

23

Issue of the periodical within the volume

46

Country of publishing house

GB - UNITED KINGDOM

Number of pages

9

Pages from-to

26501-26509

UT code for WoS article

000720960400001

EID of the result in the Scopus database

2-s2.0-85120735982