i-Motif DNA structures upon electric field exposure: completing the map of induced genetic errors

Electromagnetic bioeffects: a multiscale molecular simulation perspective

“…5, left). 143 Intriguingly, these calculations indicated that this dimer is significantly affected by weaker EFs (∼0.5 V nm −1 ), which block normal proton exchange between the C nucleobases (see Fig. 5, right).…”

“…5, right). 143 In the absence of external EF, the CH + :C and C:CH + base-pairs are degenerate with the central proton undergoing rapid exchange ( k trans ∼ 10 11 s −1 ). 143 However, in the presence of a 0.5–2.0 V nm −1 EF, the C:CH + configuration (relative to the applied EF) is 6–27 kJ mol −1 more stable than its CH + :C counterpart.…”

“…143 In the absence of external EF, the CH + :C and C:CH + base-pairs are degenerate with the central proton undergoing rapid exchange ( k trans ∼ 10 11 s −1 ). 143 However, in the presence of a 0.5–2.0 V nm −1 EF, the C:CH + configuration (relative to the applied EF) is 6–27 kJ mol −1 more stable than its CH + :C counterpart. 143 As this exchange process plays a fundamental role in delocalising the cationic character of the CH + :C base-pairs, it mitigates the risk of side-reactions with the surrounding molecules ( e.g.…”

“…143 However, in the presence of a 0.5–2.0 V nm −1 EF, the C:CH + configuration (relative to the applied EF) is 6–27 kJ mol −1 more stable than its CH + :C counterpart. 143 As this exchange process plays a fundamental role in delocalising the cationic character of the CH + :C base-pairs, it mitigates the risk of side-reactions with the surrounding molecules ( e.g. oxidation by water).…”

“…oxidation by water). 143 By blocking this exchange process, external EFs effectively localise the cationic character of i-motifs onto a single C base, which may increase the probability of deleterious reactions with the surrounding media. 143…”