Competition between polysaccharide/polynucleotide complexation vs.polynucleotide hybridization; Salt concentration dependence of the reaction direction

A single chain of schizophyllan (β-(1→3)-D-glucan) formed a complex with a homo-polynucleotide. In this paper, using adenine-thymine (or uracil) double strand as a model system, we explored whether s-SPG can unzip polynucleotide duplexes, examining the competition between the schizophyllan/polynucleotide complexation and the polynucleotide hybridization with circular dichroism at various NaCl concentrations. The unzipping reaction happened for the hetero-duplexes (i.e., RNA-DNA duplexes) at low salt concentrations, on the other hand, it was not observed for the homo-duplexes at all the salt concentrations.