Polynucleotides. XXVI. Complex formation of polynucleotides derived from formycin and laurusin with cyclonucleoside oligonucleotides.

Poly(formycin phosphate) and poly(laurusin phosphate) were synthesized by polymerizing formycin and laurusin 5'-diphosphate by means of E. coli polynucleotide phosphorylase. The complex formation of these polynucleotides with cyclonucleoside polynucleotides were investigated. While poly(formycin phosphate) did not form the complex with an octanucleotide of 6,2'-anhydro-6-oxy-1-beta-D-arabinofuranosyluracil, poly(laurusin phosphate) did form a 1: 1 complex with octanucleotide of 8,2'-anhydro-8-mercapto-9-beta-D-arabinofuranosyladenine in the presence of 0.15M Na ion at neutrality and 3(o). CD spectrum of this complex showed a couple of a trough at 286 nm and a peak at 262 nm. This fact suggests that the complex has a left-handed helical conformation, which is opposite to the natural double helical polynucleotides. The cause of this phenomenon was discussed in connection with the complex of cyclonucleoside oligonucleotides.