Low energy electron induced damage to plasmid DNA pQE30

Kumar, Shiv; Pota, Tasneem; Dinakar, P.; Dongre, Anushka; Rao, Basuthkar J.

doi:10.1063/1.4737182

Cited by 24 publications

(19 citation statements)

References 36 publications

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“…An alternative pathway for dissociation after electron attachment is autoionization of the extra electron accompanied by excitation into a dissociative state (neutral dissociation). DNA single‐strand breaks can be induced by LEEs via DEA within several resonances below 12 eV (depending on the system under study resonances peaking around 10, 7, 5.5, 2.2 and 1 eV have been reported) . In a very recent study the energy‐dependence of LEE‐induced strand breakage in two different oligonucleotides has been determined .…”

Section: Introductionmentioning

confidence: 99%

Low‐Energy Electron‐Induced Strand Breaks in Telomere‐Derived DNA Sequences—Influence of DNA Sequence and Topology

Rackwitz

Bald

2018

Chemistry A European J

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During cancer radiation therapy high-energy radiation is used to reduce tumour tissue. The irradiation produces a shower of secondary low-energy (<20 eV) electrons, which are able to damage DNA very efficiently by dissociative electron attachment. Recently, it was suggested that low-energy electron-induced DNA strand breaks strongly depend on the specific DNA sequence with a high sensitivity of G-rich sequences. Here, we use DNA origami platforms to expose G-rich telomere sequences to low-energy (8.8 eV) electrons to determine absolute cross sections for strand breakage and to study the influence of sequence modifications and topology of telomeric DNA on the strand breakage. We find that the telomeric DNA 5'-(TTA GGG) is more sensitive to low-energy electrons than an intermixed sequence 5'-(TGT GTG A) confirming the unique electronic properties resulting from G-stacking. With increasing length of the oligonucleotide (i.e., going from 5'-(GGG ATT) to 5'-(GGG ATT) ), both the variety of topology and the electron-induced strand break cross sections increase. Addition of K ions decreases the strand break cross section for all sequences that are able to fold G-quadruplexes or G-intermediates, whereas the strand break cross section for the intermixed sequence remains unchanged. These results indicate that telomeric DNA is rather sensitive towards low-energy electron-induced strand breakage suggesting significant telomere shortening that can also occur during cancer radiation therapy.

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Section: Introductionmentioning

confidence: 99%

Low‐Energy Electron‐Induced Strand Breaks in Telomere‐Derived DNA Sequences—Influence of DNA Sequence and Topology

Rackwitz

Bald

2018

Chemistry A European J

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“…Investigations, along these lines, so far, reported that electrons with very low energy (0-3 eV) can induce DNA damage either in the form of strand breaks, nucleobase release, or cross linking and dimer formation, etc. 4, 12,19,[22][23][24] In particular, remarkable observations on DNA damage as single strand breaks (SSBs), double strand breaks (DSBs), and its mechanistic pathway were made initially by Sanche and co-workers in the early years of the last decade. 12 Sanche's group discussed the strand breaks in a dry plasmid DNA arising as a result of resonant electron attachment to the DNA constituents.…”

Section: Introductionmentioning

confidence: 99%

“…12 This observation later spawned a new beginning in the field of resonant electronmolecule scattering. Most of the experiments those came up later with the fact that SSB, 11,[22][23][24]11,22,23 and multiple double strand break (MDSB), 11 etc., can be observed within the energy regime of 0.1-100 eV.…”

Section: Introductionmentioning

confidence: 99%

Effect of quantum tunneling on single strand breaks in a modeled gas phase cytidine nucleotide induced by low energy electron: A theoretical approach

Bhaskaran

Sarma

2013

The Journal of Chemical Physics

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Effect of quantum mechanical tunneling on single strand breaks induced by low energy electron (LEE) has been investigated in a modeled gas phase system, 2'-deoxycytidine-3'-monophosphate (3'-dCMPH). The potential energy curves for the sugar-phosphate C-O (3' C-O) bond cleavage have been generated using second order Møller-Plesset perturbation theory at the 6-31+G(d) accuracy level. Results from the electronic structure theory calculations in conjunction with our time dependent calculations for the 3' C-O bond rupture in 3'-dCMPH using local complex potential based time dependent wave packet approach show significant quantum tunneling of the 3' C-O bond from the bound vibrational states above 1 eV of the anionic potential energy curve. A comparison of the fragmentation profile with that of our earlier gas phase investigations based on Hartree-Fock and density functional theory--Becke, 3-parameter, Lee-Yang-Parr methods with 6-31+G(d) basis set is also provided. Further, inspection of the singly occupied molecular orbitals generated at different 3' C-O bond lengths clearly indicates the electron transfer from the low lying base-π(∗) shape resonance state to the phosphate P = O π(∗) orbital of the DNA backbone during the strand breaks. The decisive step during LEE induced strand breaks follows via "charge induced dissociation" (CID) for the metastable anion formed below 1 eV, whereas quantum mechanical tunnel-ing is out-weighted the CID mechanism for the LEE above 1 eV.

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“…In many of these investigations the yields of specific damages, including single-and double-strand breaks (SSB and DSB) [1][2][3][4][5][6][7][8] and crosslinks (CL), 9 as well as the formation of neutral species 7,10 and stable anions 1,2 has been measured as a function of electron energy within the range 0-20 eV. Whereas the electron energy dependencies of DNA conformational changes (i.e., formation of SSB, DSB, and CL) has been observed in films of bacterial DNA, 1,3 the yield functions for other specific products were mainly obtained in experiments with films of short synthetic DNA strands, e.g., self-assembled monolayer oligonucleotides, [1][2][3]11 with lengths ranging from 3 to 40 bases.…”

Section: Introductionmentioning

confidence: 99%

Cisplatin Radiosensitization of DNA Irradiated with 2–20 eV Electrons: Role of Transient Anions

et al. 2014

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Platinum chemotherapeutic agents, such as cisplatin (cis-diamminedichloroplatinum(II)), can act as radiosensitizers when bound covalently to nuclear DNA in cancer cells. This radiosensitization is largely due to an increase in DNA damage induced by low-energy secondary electrons, produced in large quantities by high-energy radiation. We report the yields of single-and doublestrand breaks (SSB and DSB) and interduplex cross-links (CL) induced by electrons of 1.6-19.6 eV (i.e., the yield functions) incident on 5 monolayer (ML) films of cisplatin-DNA complexes. These yield functions are compared with those previously recorded with 5 ML films of unmodified plasmid DNA. Binding of five cisplatin molecules to plasmid DNA (3197 base pairs) enhances SSB, DSB, and CL by factors varying, from 1.2 to 2.8, 1.4 to 3.5, and 1.2 to 2.7, respectively, depending on electron energy. All yield functions exhibit structures around 5 and 10 eV that can be attributed to enhancement of bond scission, via the initial formation of core-excited resonances associated with π → π* transitions of the bases. This increase in damage is interpreted as arising from a modification of the parameters of the corresponding transient anions already present in nonmodified DNA, particularly those influencing molecular dissociation. Two additional resonances, specific to cisplatin-modified DNA, are formed at 13.6 and 17.6 eV in the yield function of SSB. Furthermore, cisplatin binding causes the induction of DSB by electrons of 1.6-3.6 eV, i.e., in an energy region where a DSB cannot be produced by a single electron in pure DNA. Breaking two bonds with a subexcitation-energy electron is tentatively explained by a charge delocalization mechanism, where a single electron occupies simultaneously two σ* bonds linking the Pt atom to guanine bases on opposite strands.

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Low energy electron induced damage to plasmid DNA pQE30

Cited by 24 publications

References 36 publications

Low‐Energy Electron‐Induced Strand Breaks in Telomere‐Derived DNA Sequences—Influence of DNA Sequence and Topology

Low‐Energy Electron‐Induced Strand Breaks in Telomere‐Derived DNA Sequences—Influence of DNA Sequence and Topology

Effect of quantum tunneling on single strand breaks in a modeled gas phase cytidine nucleotide induced by low energy electron: A theoretical approach

Cisplatin Radiosensitization of DNA Irradiated with 2–20 eV Electrons: Role of Transient Anions

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