Chirality: Amplification of chirality in PNA: PNA duplexes is limited

Peptide nucleic acids (PNAs) are a chimera of peptides and nucleic acids with several of the properties normally associated with DNA including base pairing but with prominent differences including the absence of the sugar moieties and the phosphate groups which play important roles in DNA. The absence of the deoxyribose group means that the PNA, which apparently forms a double helix, has no information to choose left from right in comparison to the B-DNA double helix which is right handed. The absence of the phosphate group means that PNA is not a polyelectrolyte as is the situation in DNA. Studies of PNA can therefore yield insight into how the DNA structure depends on chirality and polyelectrolyte function. In the work described below such studies reveal the conformational disorder of PNA and allow insight into the role of chiral amplification. These studies may play a role in speculations that the earliest life forms may have depended on PNA.