The Elusive Noncanonical Isomers of Ionized 9-Methyladenine and 2'-Deoxyadenosine
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388963%3A_____%2F21%3A00541226" target="_blank" >RIV/61388963:_____/21:00541226 - isvavai.cz</a>
Result on the web
<a href="https://doi.org/10.1021/acs.jpca.0c10293" target="_blank" >https://doi.org/10.1021/acs.jpca.0c10293</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1021/acs.jpca.0c10293" target="_blank" >10.1021/acs.jpca.0c10293</a>
Alternative languages
Result language
angličtina
Original language name
The Elusive Noncanonical Isomers of Ionized 9-Methyladenine and 2'-Deoxyadenosine
Original language description
Noncanonical nucleobases and nucleosides represent newly discovered species of relevance for DNA ionization. We report a targeted synthesis of gas-phase 9-methylene(1H)adenine cation radical (2(+center dot)) as a low-energy isomer of ionized 9-methyladenine. Ion 2(+center dot) showed unique collision-induced dissociation and UV-vis photodissociation action spectra that distinguished it from other cation radical isomers. Ab initio energy calculations with coupled cluster theory extrapolated to the complete basis set limit, CCSD(T)/CBS, identified cation radical 2(+center dot) as the global energy minimum of the adenine-related C6H7N5+center dot isomers. The action spectrum of 2(+center dot) was assigned on the basis of vibronic absorption spectra that were calculated with time-dependent density functional theory for multiple vibrational configurations of thermal ions. The major dissociation of 2(+center dot) proceeded by hydrogen loss that was elucidated by deuterium labeling at the exchangeable N-1 and NH2 positions and C-8 position and by kinetic analysis. The dissociation involved a reversible rearrangement to intermediate dihydropteridine structures, yielding a protonated aminopteridine as the product, which was identified by multistep UV-vis action spectroscopy. We also report a computational study of related noncanonical isomers of 2'-deoxyadenosine cation radical having the radical defect at C-1' that were found to be thermodynamically more stable than the canonical isomer in both the gas phase and aqueous solution. The noncanonical isomers were calculated to have extremely low ion-electron recombination energies of 4.42-5.10 eV that would make them dead-end hole traps if produced by DNA ionization.
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
<a href="/en/project/LTAUSA19094" target="_blank" >LTAUSA19094: Electron and proton transfer in ionized DNA fragments</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2021
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
1520-5215
Volume of the periodical
125
Issue of the periodical within the volume
1
Country of publishing house
US - UNITED STATES
Number of pages
11
Pages from-to
338-348
UT code for WoS article
000611410000037
EID of the result in the Scopus database
2-s2.0-85099092775