Base Intercalation in DNA
Intercalation is the stacking of a molecule between two bases in DNA (within one strand). This is a common process with a number of aromatic molecules and is driven by π- π, hydrophobic, steric, and other interactions.
One important mechanism in the interaction of carcinogens with DNA is base intercalation. This phenomenon is common with polycyclic aromatic structures, e.g., polycyclic aromatic hydrocarbons and aflatoxin B1. The process involves “stacking” of an aromatic ring(s) between two bases, particularly purines. The physical chemistry involves π interactions between the rings, allowing the carcinogen to slip in between two bases, in a sandwich mode.