Photoinduced charge separation and DNA self-repair depend on sequence directionality and stacking pattern

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081707%3A_____%2F24%3A00600749" target="_blank" >RIV/68081707:_____/24:00600749 - isvavai.cz</a>

Alternative codes found

RIV/61989592:15640/24:73624534

Result on the web

<a href="https://pubs.rsc.org/en/content/articlelanding/2024/sc/d3sc04971j" target="_blank" >https://pubs.rsc.org/en/content/articlelanding/2024/sc/d3sc04971j</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/d3sc04971j" target="_blank" >10.1039/d3sc04971j</a>

Result language

angličtina

Original language name

Photoinduced charge separation and DNA self-repair depend on sequence directionality and stacking pattern

Original language description

Charge separation is one of the most common consequences of the absorption of UV light by DNA. Recently, it has been shown that this process can enable efficient self-repair of cyclobutane pyrimidine dimers (CPDs) in specific short DNA oligomers such as the GAT00000000000000000000000000000000111111110000000011111111000000000000000000000000T sequence. The mechanism was characterized as sequential electron transfer through the nucleobase stack which is controlled by the redox potentials of nucleobases and their sequence. Here, we demonstrate that the inverse sequence TTAG promotes self-repair with higher quantum yields (0.58 +/- 0.23%) than GATT (0.44 +/- 0.18%) in a comparative study involving UV-irradiation experiments. After extended exposure to UV irradiation, a photostationary equilibrium between self-repair and damage formation is reached at 33 +/- 13% for GATT and at 40 +/- 16% for TTAG, which corresponds to the maximum total yield of self-repair. Molecular dynamics and quantum mechanics/molecular mechanics (QM/MM) simulations allowed us to assign this disparity to better stacking overlap between the G and A bases, which lowers the energies of the key A-G+ charge transfer state in the dominant conformers of the TTAG tetramer. These conformational differences also hinder alternative photorelaxation pathways of the TTAG tetranucleotide, which otherwise compete with the sequential electron transfer mechanism responsible for CPD self-repair. Overall, we demonstrate that photoinduced electron transfer is strongly dependent on conformation and the availability of alternative photodeactivation mechanisms. This knowledge can be used in the identification and prediction of canonical and modified DNA sequences exhibiting efficient electron transfer. It also further contributes to our understanding of DNA self-repair and its potential role in the photochemical selection of the most photostable sequences on the early Earth.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10401 - Organic chemistry

Project

<a href="/en/project/GA21-23718S" target="_blank" >GA21-23718S: The fascinating physical chemistry of DNA studied by advanced computations</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2024

Confidentiality

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

Name of the periodical

Chemical Science

ISSN

2041-6520

e-ISSN

2041-6539

Volume of the periodical

15

Issue of the periodical within the volume

6

Country of publishing house

GB - UNITED KINGDOM

Number of pages

9

Pages from-to

2158-2166

UT code for WoS article

001138279200001

EID of the result in the Scopus database

2-s2.0-85182366023