Strong and weak hydrogen bonds in drug-DNA complexes: a statistical analysis

Area of Science:

• Structural Biology
• Medicinal Chemistry
• Computational Chemistry

Background:

• Hydrogen bonds are critical for molecular recognition in biological systems.
• The role of weak hydrogen bonds in drug-DNA interactions is often underestimated.
• Understanding these interactions is key to designing effective therapeutics.

Purpose of the Study:

• To statistically analyze strong and weak hydrogen bonds in drug-DNA complexes.
• To investigate the role of these bonds in the minor groove of DNA.
• To generate recognition geometries for amidinium-based inhibitors of Human African Trypanosomes (HAT).

Main Methods:

• Statistical analysis of 70 drug-DNA complexes from the Protein Data Bank (PDB).
• Utilized an in-house software, hydrogen bond analysis tool (HBAT).
• Generated virtual geometries using a docking study for HAT inhibitors.

Main Results:

• Weak hydrogen bonds (e.g., C-H...O) are ubiquitous, with an average ratio of 1.4 weak to 1 strong bond.
• N3 of purine and O2 of pyrimidine are favored acceptors for both bond types.
• Donor multifurcation (bifurcation and trifurcation) is common, especially with drug molecule donors.

Conclusions:

• Both strong and weak hydrogen bonds significantly contribute to molecular recognition in drug-DNA complexes.
• The geometries of weak hydrogen bonds are variable but important for binding.
• Generated virtual geometries correlate with published activities, supporting the optimization of hydrogen bonds in active sites.