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Exciton Absorption and Luminescence in i-Motif DNA
We have studied the excited-state dynamics for the i-motif form of cytosine chains (dC)(10), using the ultrafast fluorescence up-conversion technique. We have also calculated vertical electronic transition energies and determined the nature of the corresponding excited states in a model tetramer i-m...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group UK
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6831829/ https://www.ncbi.nlm.nih.gov/pubmed/31690734 http://dx.doi.org/10.1038/s41598-019-52242-1 |
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author | Reveguk, Zakhar V. Khoroshilov, Evgeny V. Sharkov, Andrey. V. Pomogaev, Vladimir A. Buglak, Andrey A. Tarnovsky, Alexander N. Kononov, Alexei I. |
author_facet | Reveguk, Zakhar V. Khoroshilov, Evgeny V. Sharkov, Andrey. V. Pomogaev, Vladimir A. Buglak, Andrey A. Tarnovsky, Alexander N. Kononov, Alexei I. |
author_sort | Reveguk, Zakhar V. |
collection | PubMed |
description | We have studied the excited-state dynamics for the i-motif form of cytosine chains (dC)(10), using the ultrafast fluorescence up-conversion technique. We have also calculated vertical electronic transition energies and determined the nature of the corresponding excited states in a model tetramer i-motif structure. Quantum chemical calculations of the excitation spectrum of a tetramer i-motif structure predict a significant (0.3 eV) red shift of the lowest-energy transition in the i-motif form relative to its absorption maximum, which agrees with the experimental absorption spectrum. The lowest excitonic state in i-(dC)(10) is responsible for a 2 ps red-shifted emission at 370 nm observed in the decay-associated spectra obtained on the femtosecond time-scale. This delocalized (excitonic) excited state is likely a precursor to a long-lived excimer state observed in previous studies. Another fast 310 fs component at 330 nm is assigned to a monomer-like locally excited state. Both emissive states form within less than the available time resolution of the instrument (100 fs). This work contributes to the understanding of excited-state dynamics of DNA within the first few picoseconds, which is the most interesting time range with respect to unraveling the photodamage mechanism, including the formation of the most dangerous DNA lesions such as cyclobutane pyrimidine dimers. |
format | Online Article Text |
id | pubmed-6831829 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
spelling | pubmed-68318292019-11-13 Exciton Absorption and Luminescence in i-Motif DNA Reveguk, Zakhar V. Khoroshilov, Evgeny V. Sharkov, Andrey. V. Pomogaev, Vladimir A. Buglak, Andrey A. Tarnovsky, Alexander N. Kononov, Alexei I. Sci Rep Article We have studied the excited-state dynamics for the i-motif form of cytosine chains (dC)(10), using the ultrafast fluorescence up-conversion technique. We have also calculated vertical electronic transition energies and determined the nature of the corresponding excited states in a model tetramer i-motif structure. Quantum chemical calculations of the excitation spectrum of a tetramer i-motif structure predict a significant (0.3 eV) red shift of the lowest-energy transition in the i-motif form relative to its absorption maximum, which agrees with the experimental absorption spectrum. The lowest excitonic state in i-(dC)(10) is responsible for a 2 ps red-shifted emission at 370 nm observed in the decay-associated spectra obtained on the femtosecond time-scale. This delocalized (excitonic) excited state is likely a precursor to a long-lived excimer state observed in previous studies. Another fast 310 fs component at 330 nm is assigned to a monomer-like locally excited state. Both emissive states form within less than the available time resolution of the instrument (100 fs). This work contributes to the understanding of excited-state dynamics of DNA within the first few picoseconds, which is the most interesting time range with respect to unraveling the photodamage mechanism, including the formation of the most dangerous DNA lesions such as cyclobutane pyrimidine dimers. Nature Publishing Group UK 2019-11-05 /pmc/articles/PMC6831829/ /pubmed/31690734 http://dx.doi.org/10.1038/s41598-019-52242-1 Text en © The Author(s) 2019 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. |
spellingShingle | Article Reveguk, Zakhar V. Khoroshilov, Evgeny V. Sharkov, Andrey. V. Pomogaev, Vladimir A. Buglak, Andrey A. Tarnovsky, Alexander N. Kononov, Alexei I. Exciton Absorption and Luminescence in i-Motif DNA |
title | Exciton Absorption and Luminescence in i-Motif DNA |
title_full | Exciton Absorption and Luminescence in i-Motif DNA |
title_fullStr | Exciton Absorption and Luminescence in i-Motif DNA |
title_full_unstemmed | Exciton Absorption and Luminescence in i-Motif DNA |
title_short | Exciton Absorption and Luminescence in i-Motif DNA |
title_sort | exciton absorption and luminescence in i-motif dna |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6831829/ https://www.ncbi.nlm.nih.gov/pubmed/31690734 http://dx.doi.org/10.1038/s41598-019-52242-1 |
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