DNA double strand cleavage via interstrand hydrogen atom abstraction.

Double strand breaks (DSBs) are the most deleterious form of DNA damage. Natural products that produce them are potent cytotoxic agents. Designing molecules that produce DSBs via a single chemical event is challenging. We determined that formation of a C4'-nucleotide radical in duplex DNA under aerobic conditions gives rise to a DSB. The original radical yields a strand break containing a peroxyl radical, which initiates opposite strand cleavage via C4'-hydrogen atom abstraction. This mechanism provides the impetus to design DNA damaging agents that produce DSBs by abstracting a single hydrogen atom from the biopolymer.