Shape Resonances in DNA: Nucleobase Release, Reduction, and Dideoxynucleoside Products Induced by 1.3 to 2.3 eV Electrons

Kumari, Bhavini; Huwaidi, Alaa; Robert, Gabriel; Cloutier, Pierre; Bass, A. D.; Sanche, Léon; Wagner, J. Richard

doi:10.1021/acs.jpcb.2c01851

Cited by 9 publications

(17 citation statements)

References 64 publications

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“…In the past two decades, a large number of experimental studies have been reported in the literature which have investigated the interaction of LEEs with DNA. − One of the first experimental studies on electron attachment-induced DNA strand breaks was reported by Sanche and co-workers, where dry DNA, having only the structural water molecules intact, was exposed to electrons having kinetic energies as low as 3.5 eV. Gel electrophoresis of the DNA sample was performed to quantify the damaged (SSBs and DSBs) and undamaged DNA.…”

Section: Mechanism Of Tni-induced Dna Damagementioning

confidence: 99%

“…LC-MS/MS analysis of the products further showed that only a minor quantity of the products was formed due to base release. However, when the model DNA systems were changed to a 16-mer oligonucleotide, unaltered nucleobase formed due to sugar–nucleobase rupture was the major DEA product . They attribute this observation to the delocalization of the additional electron within the long DNA strand.…”

Section: Summary Of Dna Strand-break Mechanismsmentioning

confidence: 99%

“…However, when the model DNA systems were changed to a 16-mer oligonucleotide, unaltered nucleobase formed due to sugar−nucleobase rupture was the major DEA product. 76 They attribute this observation to the delocalization of the additional electron within the long DNA strand. The last pathway of sugar−phosphate bond break involves initial electron attachment to form a dipole-bound anion (see Scheme 7).…”

Section: Mechanismsmentioning

confidence: 99%

“…The formation of the TNI* could also lead to the rupture of the molecule and is known as DEA (Scheme ). ,− Interaction of LEE with DNA results in the formation of SSBs, DSBs, base release, cross-links, multiple damage sites, etc., via DEA. − Theoretical modeling of DEA is highly challenging because it involves the coupling between nuclear and electronic degrees of freedom of a molecule . At the same time, the TNIs are difficult to characterize experimentally due to their short lifetimes.…”

Section: Introductionmentioning

confidence: 99%

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Secondary Electron Attachment-Induced Radiation Damage to Genetic Materials

Tripathi

Verma

et al. 2023

ACS Omega

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Reactions of radiation-produced secondary electrons (SEs) with biomacromolecules (e.g., DNA) are considered one of the primary causes of radiation-induced cell death. In this Review, we summarize the latest developments in the modeling of SE attachmentinduced radiation damage. The initial attachment of electrons to genetic materials has traditionally been attributed to the temporary bound or resonance states. Recent studies have, however, indicated an alternative possibility with two steps. First, the dipole-bound states act as a doorway for electron capture. Subsequently, the electron gets transferred to the valence-bound state, in which the electron is localized on the nucleobase. The transfer from the dipole-bound to valencebound state happens through a mixing of electronic and nuclear degrees of freedom. In the presence of aqueous media, the water-bound states act as the doorway state, which is similar to that of the presolvated electron. Electron transfer from the initial doorway state to the nucleobase-bound state in the presence of bulk aqueous media happens on an ultrafast time scale, and it can account for the decrease in DNA strand breaks in aqueous environments. Analyses of the theoretically obtained results along with experimental data have also been discussed.

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Section: Mechanism Of Tni-induced Dna Damagementioning

confidence: 99%

Section: Summary Of Dna Strand-break Mechanismsmentioning

confidence: 99%

Section: Mechanismsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Secondary Electron Attachment-Induced Radiation Damage to Genetic Materials

Tripathi

Verma

et al. 2023

ACS Omega

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“…Many experimental − and theoretical − works have been conducted to unravel the intricacies of the process of LEE attachment to DNA and its subsequent damage. Since DNA is a macromolecule, the entire DNA or RNA strand cannot be simulated using the existing quantum chemical techniques due to computational bottlenecks.…”

Section: Introductionmentioning

confidence: 99%

Electron Attachment to Wobble Base Pairs

Bachhar

Tripathi

et al. 2023

J. Phys. Chem. A

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We have analyzed the low-energy electron attachment to wobble base pairs using the equation of motion coupled cluster method and extended basis sets. A doorway mechanism exists for the attachment of the additional electron to the base pairs, where the initially formed dipole-bound anion captures the incoming electron. The doorway dipole-bound anionic state subsequently leads to the formation of a valence-bound state, and the transfer of extra electron occurs by mixing of electronic and nuclear degrees of freedom. The formation of the valence-bound anion is associated with proton transfer in hypoxanthine–cytosine and hypoxanthine–adenine base pairs, which happens through a concerted electron–proton transfer process. The calculated rate constant for the dipole-bound to valence-bound transition in wobble base pairs is slower than that observed in the Watson–Crick guanine–cytosine base pair.

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