Skip to content

Atomic-scale insight into the interactions between hydroxyl radicals and DNA in solution using the ReaxFF reactive force field

Evidence and attribution

Authority of statements

Prose sections below (Summary, Methods, Findings, etc.) are curated summaries of the publication identified by doi, title, and pdf_path in the front matter above. They are not new primary claims by this wiki.

For definitive numerical values, reaction schemes, and interpretations, use the peer-reviewed article (and optional records under normalized/papers/ when present)—not this page alone.

Summary

This New Journal of Physics article uses ReaxFF reactive molecular dynamics to follow how reactive oxygen species, especially hydroxyl radicals, attack a short DNA duplex in explicit water at room temperature—chemistry that fixed-bond force fields cannot represent. The motivation is plasma-medicine and oxidative-stress contexts where short-lived radicals reach biomolecules in solution. The work is a collaboration between Antwerp-led groups and Penn State contributors on the reactive force-field side. The abstract emphasizes bond-making and bond-breaking at nucleobases and backbone sites rather than elastic deformation of a frozen topology.

Methods

Reactive molecular dynamics uses ReaxFF in LAMMPS on a 12 base-pair DNA dodecamer in explicit water in a 33 × 33 × 48 Å three-dimensionally periodic supercell at roughly ~1 g mL⁻¹ liquid density, with reactive oxygen species added for impact trajectories. After minimization, the protocol ramps temperature 0 → 300 K over 100 ps, holds 300 K for 200 ps, then continues NVT equilibration for 300 ps total with a Nosé–Hoover thermostat (coupling 25 fs). Production consists of 15 independent 500 ps impact trajectories at 300 K with 0.25 fs timestep. No barostat, controlled pressure, electric field, or enhanced sampling is used; electrostatics follow the ReaxFF formulation (Coulomb plus QEq-style charges) with parameter lineage cited in the article.

Force-field training: N/A — the work applies a published CH(O/N)-class ReaxFF parametrization adapted for DNA and cites prior biomolecular parametrizations; it does not report a new global ReaxFF optimization.

Static QM / DFT: N/A — the centerpiece is ReaxFF dynamics; DFT appears through citations to prior validation of related parametrizations, not as new barrier or pathway production calculations in this study.

Findings

The trajectories show ·OH-driven bond-making and bond-breaking at nucleobases and backbone sites, including 8-OH-adduct radicals on the path to 8-oxoGuanine- and 8-oxoAdenine-like motifs, H-abstraction from amines, and partial opening of loose DNA ends in water, as discussed with figures in papers/Verlackt_njp_DNA_2015.pdf. H₂O₂ and HO₂ are in the reactive set; the abstract notes H₂O₂ is largely unreactive on the simulated time scale relative to ·OH. The paper is simulation-forward: plasma–DNA experiments motivate the problem but are not used as quantitative fits at abstract level. Fifteen parallel runs sample stochastic attack; OH-terminated terminal bases are excluded from analyzed reaction statistics so end effects do not dominate pathway counts. Population timelines and numerical details should be read from the journal figures; the authors discuss force-field bias in rare channels and the gap to long biological timescales in the Discussion.

Limitations

  • Force-field bias in rare reaction channels; statistical sampling over long biological times remains approximate.
  • DNA sequence / secondary structure dependence is only partially explored in any single study.

Relevance to group

Demonstrates ReaxFF deployment outside traditional materials catalysis—here soft matter + plasma chemistry—with direct van Duin group authorship.

Citations and evidence anchors

  • Title page and abstract in papers/Verlackt_njp_DNA_2015.pdf; DOI: 10.1088/1367-2630/17/10/103005.

Reader notes (navigation)