The Elusive Noncanonical Isomers of Ionized 9-Methyladenine and 2'-Deoxyadenosine

Kód výsledku v 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>

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

The Elusive Noncanonical Isomers of Ionized 9-Methyladenine and 2'-Deoxyadenosine

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

The Elusive Noncanonical Isomers of Ionized 9-Methyladenine and 2'-Deoxyadenosine

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

<a href="/cs/project/LTAUSA19094" target="_blank" >LTAUSA19094: Přenos elektronu a protonu v ionizovaných fragmentech DNA</a><br>

Návaznosti

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

Rok uplatnění

2021

Kód důvěrnosti údajů

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

Název periodika

Journal of Physical Chemistry A

ISSN

1089-5639

e-ISSN

1520-5215

Svazek periodika

125

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

11

Strana od-do

338-348

Kód UT WoS článku

000611410000037

EID výsledku v databázi Scopus

2-s2.0-85099092775