[Interaction of tripeptides containing arginine and tyrosine (or phenylalanine) residues with synthetic polynucleotides and DNA of various origins].

Model peptides--L-Arg-Gly-L-Arg, L-Arg-L-Tyr-L-Arg and L-Arg-L-Phe-L-Arg bind to different DNAs and synthetic polynucleotides and are found in the major groove of the double helix. Polynucleotide complexes containing L-Arg-Gly-L-Arg were studied in order to consider the influence of the arginine residues on the polynucleotide melting temperature. It was shown, that L-Arg-L-Tyr-L-Arg and L-Arg-L-Phe--L-Arg lowers the melting temperature in all polynucleotides studied. The dependence of the melting temperature of polynucleotide (DNA)--L-Arg-L-Tyr(L-Phe)-L-Arg complexes upon the polynucleotide GC-content has been detected. These effects reflect the intercalation of peptide tyrosyl (or phenylalanyl) residues into the double-stranded polynucleotide.