AFFINITY MODIFICATION OF AMINO-ACID DERIV ATIVES OF OLIGONUCLEOTIDES IN COMPLEMENTARY COMPLEX

Intracomplex photochemical interaction of. photoactive derivatives R-C ONH(CH2)(3)NH-pGATACCAA, where R = p-azidotetrafluorophenyl (I) or 2-n itro-5-azidophenyl (II), and 5'-phospho-p-azidoanilide pGATACCAA (III) with a target - oligonucleotide pGGTATCp (IV) and its derivatives '' pGGTATCp-NH(CH2)(3)NHX, where X = H (V), Phe (VI), or Lys (VII), was s tudied. According to electrophoretic data, photoreagent (I) gives rise to a covalent photoadduct with compound (IV) as well as with derivati ves (VI) and (VII). In the case of reagent (II), only targets (V) - (V II) including aliphatic amino groups participate in the photocoupling. Upon irradiation of the duplexes comprising photoreagent (III) and ta rgets (V) - (VII), the process is accompanied by the cleavage of the r eagent's oligonucleotide moiety off the photomodification product. A p lausible mechanism of the cleavage is discussed.