A quantum mechanical model for hole transport through DNA: predicting conditions for oscillatory/non-oscillatory behavior

A quantum mechanical model that considers tunneling and inelastic scattering has been applied to explain the hole transfer reaction from a G (Guanine) base to a GGG base cluster through a barrier of Adenine bases, (A)n (n = 1-16). For n = 1, the ratio of tunneling to inelastic scattering is about 6, which is sharply decreased to around 0.23 and 5.23 × 10-8 for n = 4 and 16 respectively, suggesting dominance of inelastic scattering for n ≥ 4. As in experiment, the calculated product yield ratios (PGGG) exhibit a strong distance dependence for n < 4, and a weak distance dependence for n ≥ 4. We also predict conditions under which oscillatory or non-oscillatory charge transfer (CT) yield are expected. .