NMR Study of the p-DNA duplex [(4 '-> 2 ')-3 '-desoxyribopyranosyl((m5)CGDDTT(m5)CG)(2)] and comparison with its p-RNA analogue

The determination of the solution structure of small non-natural oligopepti des and oligonucleotides by NMR, which is one of the main research topics o f our group, is illustrated on the example of an 8-mer p-DNA duplex. p-DNA, the 3'-desoxy analogue of p-RNA, forms an highly selective pairing system but its pairing strength is less than that of analogous p-RNA sequences. Th e NMR study reveals that the backbone of p-DNA corresponds more closely to the conformation predicted for pentapyranose nucleic acids by qualitative c onformational analysis than p-RNA.