| Abstract;The PNA(Peptide Nucleic Acid) is a DNA analog which has nucleobases and a polyamide backbone. Due to its high affinity to DNA and RNA, PNA will be a useful material in biological field. In this study, we studied effect of cations on the formation of PNA/DNA hybrids. As a result, the stability (-.DELTA.G.DEG.37) of nucleic acids increased with increasing sodium ion concentration from 0.01M to 1M. In contrast, for PNA/DNA hybrid, when sodium ion concentration has increased from 0 to 1M, the -.DELTA.G.DEG.37 value decreased or little changed as shown in Figure 1. The results suggest that effect of Na+ on the formation may be different between nucleic acids and PNA/DNA hybrids. Furthermore, we investigated stability of PNA/PNA duplexes with various cations (Na+,Mg2+,Mn2+, and Ni2+). As a result, melting temperatures of 100.MU.M pna(CCGACG)/pna(CGTCGG) with Na+, Mg2+, Mn2+, and Ni2+ cations were 57.9, 56.9, 49.9, and 55.1.DEG.C., respectively. The result suggests that effect of these cations on the duplex stability are different. (author abst.) |
