[Complementary-addressed modification of a single-stranded DNA fragment with an iron-porphyrin oligonucleotide derivative].

Hemin was attached covalently to the 5'-terminus of the 14-mer d(pTGACCCTCTT.CCC)rA and was shown, in the presence of oxygen and a reducing agent, to be active in the cleavage of the complementary sequence (position 261-274) in a 303 nucleotide-long DNA fragment. The yield of the cleavage products reached approximately 50%, the cleavage locus comprising two bases (G275 and G276).