Insights Into Guanine Radical Cation Deprotonation Using the Quantum Mechanics and Quantum Mechanics/Molecular Mechanics (ABEEM) Methods
Abstract
In double‐stranded DNA, a rapid deprotonation of guanine radical cation (G•+) hinders the long‐distance transfer of positive charge (hole). It is significant to explore the proton transfer of G•+ for designing other DNA structures with high electrical conductivity. The deprotonation of G•+ is explored in the 1H2O, 2H2O, 3H2O, and 9H2O models by quantum mechanics (QM) method. The results indicate that the second hydration shell facilitates proton transfer. The QM/molecular mechanics (MM) (ABEEM) method accurately simulates polarization and charge transfer effects through the implementation of the reactive valence‐state electronegativity piecewise functions and setting local charge conservation conditions. The QM/MM(ABEEM) method has been developed to investigate the 9H2O model. The obtained activation energy (16.3 ± 0.8 kJ/mol) through molecular dynamics simulations is consistent with experimental data (15.1 ± 1.5 kJ/mol), demonstrating the accuracy of the QM/MM(ABEEM) method in simulating proton transfer in the DNA system. The deprotonation rate of G•+ in the free base (1.5 × 107 s−1) is faster than that of G•+ within double‐stranded DNA (106–107 s−1), which indicates that the free G base is an avoidable participant when designing hole transfer carrier due to its rapid deprotonation rate. Concurrently, the relationship between the proton transfer distance and potential barrier is monotone increasing, meaning that the long‐range proton transfer corresponds to high energy…
Read the paper
Related studies
- Chaos and quantum thermalization
- The Dalton quantum chemistry program system
- Cord Blood Leptin and Adiponectin as Predictors of Adiposity in Children at 3 Years of Age: A Prospective Cohort Study
- Quantitative metabolomics by H-NMR and LC-MS/MS confirms altered metabolic pathways in diabetes
- Stable adiabatic quantum batteries
- A novel self-lipid antigen targets human T cells against CD1c(+) leukemias
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.