Metallo-bleomycin cleaves parallel-stranded DNA similarly to B-DNA

Bleomycin (BLM)-mediated degradation of parallel-stranded (ps) DNA duplex was investigated by HPLC product analysis of the oxidized DNA fragments. It was revealed that Co– and Fe–BLMs effectively degraded a ps DNA decamer at 5′-GC site in a similar manner to that for antiparallel-stranded (aps) B-form DNA. While the strand orientations of ps and aps duplexes are quite different, metallo-BLMs still bind to ps DNA duplex and cause DNA degradation. These results indicate that metallo-BLMs productively interact with the degradable strand of both ps and aps DNA duplexes.