Electron Attachment to Wobble Base Pairs

J, Jishnu Narayanan S; Bachhar, Arnab; Tripathi, Divya; Dutta, Achintya Kumar

doi:10.1021/acs.jpca.2c07469

Cited by 2 publications

(3 citation statements)

References 87 publications

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“…153 Our recent works have demonstrated the existence of doorway mechanisms for the formation of a stable VB state of various model systems of DNA in the gas phase and under microsolvation. 128,132,[148][149][150]156 For the GC base pair, we have used the same diabatization scheme employed by Sommerfeld to obtain the coupling between DB and VB states. The W was found to be 12 meV which is 1 order of magnitude less than the vertical excitation energies at the equilibrium geometries of the diabatic states, which means that the anionic states are in the threshold of the weak coupling limit.…”

Section: State In Deamentioning

confidence: 99%

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: State In Deamentioning

confidence: 99%

Secondary Electron Attachment-Induced Radiation Damage to Genetic Materials

Tripathi

Verma

et al. 2023

ACS Omega

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“…We have recently shown that the doorway mechanism is a general pathway for electron attachment to DNA model systems. 23,25,60,61 The doorway mechanism has also been observed for nucleobases and base pairs in the condensed phase, where the water-bound state acts as the doorway state. 25,62,63 The role of water in the electron attachment process to nucleobases has also been highlighted by Matsika and co-workers.…”

Section: Introductionmentioning

confidence: 87%

“…He showed that initial electron attachment to uracil and 5-chlorouracil in the gas phase leads to the formation of a dipole-bound state, which acts as a doorway for electron capture. , The dipole-bound state subsequently gets converted into a valence-bound state, and a cut through the adiabatic potential energy surface corresponding to the transition showed an avoided crossing between the ground and the first excited state of the radical anion. We have recently shown that the doorway mechanism is a general pathway for electron attachment to DNA model systems. ,,, The doorway mechanism has also been observed for nucleobases and base pairs in the condensed phase, where the water-bound state acts as the doorway state. ,, The role of water in the electron attachment process to nucleobases has also been highlighted by Matsika and co-workers. , The formation of a stable anion through the doorway mechanism may be competitive to the resonance-based dissociative electron attachment to DNA …”

Section: Introductionmentioning

confidence: 90%

Electron Attachment to DNA: The Protective Role of Amino Acids

Verma

Dutta

2023

J. Phys. Chem. A

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We have studied the effect of amino acids on the electron attachment properties of a DNA nucleobase, with cytosine as a model system. The equation of motion coupled cluster theory with an extended basis set has been used to simulate the electron-attached state of the DNA model system. Arginine, alanine, lysine, and glycine are the four amino acids considered to investigate their role in electron attachment to a DNA nucleobase. The electron attachment to cytosine in all the four cytosine−amino acid gas-phase dimer complexes follows a doorway mechanism, where the electron gets transferred from the initial dipole-bound doorway state to the final nucleobasebound state through the mixing of electronic and nuclear degrees of freedom. When cytosine is bulk-solvated with glycine, the glycine-bound state acts as the doorway state, where the initial electron density is localized on the bulk amino acid and away from the nucleobase, thus leading to the physical shielding of the nucleobase from the incoming electron. At the same time, the presence of amino acids can increase the stability of the nucleobasebound anionic state, which can suppress the sugar−phosphate bond rupture caused by dissociative electron attachment to DNA.

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Electron Attachment to Wobble Base Pairs

Cited by 2 publications

References 87 publications

Secondary Electron Attachment-Induced Radiation Damage to Genetic Materials

Secondary Electron Attachment-Induced Radiation Damage to Genetic Materials

Electron Attachment to DNA: The Protective Role of Amino Acids

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