DNA minor groove cross-linking by pyrrolobenzodiazepine dimer (PBD dimer DNA cross-linking)

Pyrrolobenzodiazepine dimers are highly potent synthetic molecules used as cytotoxic payloads in antibody-drug conjugates for cancer therapy. After internalization into tumor cells and release from the carrier antibody, these dimers bind covalently within the minor groove of double-stranded DNA—preferentially at 5′‑purine‑guanine‑purine sequences—forming both interstrand and intrastrand cross-links between guanine bases on opposite or same strands. This unique mode of action causes persistent structural damage that blocks essential processes such as replication and transcription, resulting in rapid cell death even among non-dividing cells. The efficiency, sequence selectivity, low resistance profile, and ability to kill both dividing/non-dividing cells distinguish them from other chemotherapeutic agents like tubulin inhibitors. However, "DNA cross-linking via pyrrolobenzodiazepine dimer" is a description of a molecular mechanism rather than a discrete therapeutic target such as a receptor or enzyme; thus it is not itself considered a canonical drug target but rather describes how certain drugs exert their effect after being delivered into tumor cells via targeted therapies like ADCs.[1][2][3][4]

Other names

Pyrrolobenzodiazepine dimer-induced DNA cross-linkPBD dimer payload mechanismDNA interstrand cross-link (by PBD)Minor groove DNA alkylation (by PBD)

Covalent binding to the minor groove of double-stranded DNA, forming interstrand and intrastrand cross-links at specific guanine-rich sequences[1][2][7][9]. Induction of persistent structural damage to DNA, leading to replication arrest and cell death[1][2][3].