Oligonucleotide-selenide conjugate: synthesis and its inducible sequence-specific alkylation of DNA.

Oligonucleotide-selenium conjugate was designed and synthesized and its sequence-specific cross-linking ability was investigated. The selenide derivatives can generate covalent interstrand cross-linking with its complementary strand through the formation of o-QM intermediate induced by periodate oxidation. A cross-linking reaction yield of up to 50% was obtained. Hydroxyl radical footprinting experiment revealed that the quinone appendage specifically alkylated the cytosine base extending the duplex formed between the conjugate and the target strand.