Electronic Structure and Oxidation Dynamics in B‐DNA Sequences Under the Influence of Transition Mutations and Disorder

Charge transfer in B‐DNA oligomers following oxidation (hole creation) is investigated using the Tight Binding Fishbone Wire model: each site represents either a base pair or a backbone position, with backbone positions not directly connected. Homopolymeric sequences (e.g., 5′‐GGGGG‐3′) are employed as reference systems for their uniform on‐site energies and interaction integrals between sites. The impact of transition mutations (e.g., G → A) and structural disorder on charge transfer is examined. Disorder is introduced along the π ‐stacking pathway and at the sugar‐phosphate backbone, affecting base pair and backbone on‐site energies and interaction parameters between sites. Electronic properties and charge transfer are analyzed through the calculation of the highest occupied molecular orbital (HOMO) regime (the energy regime made by the interaction of all sites’ HOMOs) eigenstates, participation ratios, site occupation probabilities, and charge transfer rates. The lowest unoccupied molecular orbital (LUMO) regime can be treated similarly. Charge motion is also quantified using weighted mean frequencies of sites and the total weighted mean frequency of the system, with higher values corresponding to faster charge transfer. The presence of mutations and disorder is found to enhance localization and reduce transfer efficiency. These results elucidate how sequence alterations and structural disorder modulate charge transfer in DNA.