Peptide nucleic acids and their structural modifications

Peptide (polyamide) analogues of nucleic acids (PNAs) make very promising g roups of natural nucleic-acid (NA) ligands and show many other interesting properties. Two types, of these analogues may be highlighted as particularl y interesting: the first, containing a polyamide with alternating peptide/p seudopeptide bonds as its backbone, consisting of N-(aminoalkyl)amino-acid units (type I), with nucleobases attached to the backbone nitrogen with the carboxyalkyl linker; and the second, containing a backbone consisting of a mino-acid residues carrying the nucleobases in their side chains (type II). So far, these two groups have been studied most intensively. The paper des cribes main groups of peptide nucleic acids, as well as various other amino acid-derived nucleobase monomers or their oligomers, which were either stu died in order to determine their hybridisation to nucleic acids, or only di scussed with respect to their potential usefulness in the oligomerisation a nd nucleic acids binding.