Hybridization studies with chiral peptide nucleic acids

A novel class of chiral peptide nucleic acids has been synthesized in which the sugar-phosphate backbone of DNA has been replaced with the glycyl-proline backbone of both the L- and the D-configurations, nucleobases being attached through the 4-position of proline with cis-and trans-stereochemistry. The T-10 homopolymers with cis-stereochemistry in the Land D-series bind strongly to poly(dA) with T-m values of 69 and 70 degrees C, respectively. They bind more strongly to poly(rA) with T-m values of 73 and 72 degrees C, respectively, and with apparent 1:1 stoichiometry. Using a mixed sequence decamer it was found that the thermal stability of the chiral peptide nucleic acid/oligonucleotide complex was comparable to that formed by Nielsen's polyamide nucleic acid. (C) 1997 Academic Press.