Radical cation transfer in a guanine pair: an insight to the G-quadruplex structure role using constrained DFT/MM

DNA G-Quadruplex is highly sensitive to oxidation as their structures include $$\pi$$ -stacked guanine quartets allowing fast hole transfer between the nucleobases. These transfers can be described using vertical energy gap and electronic coupling different diabatic states at play in a pair. Using classical molecular dynamics simulation constrained DFT/MM implementation deMon2k, we determine these quantities for all interacting pairs of six G-quadruplex including one four corresponding folding. We then an uni-directional within quartet, with high values, which contrasts guanine, bi-directional smaller charge parameters. The influence geometrical parameters on explored, while external or internal position may impact its probability according gaps.