Duplex formation and secondary structure of γ-PNA observed by NMR and CD.
Fiche publication
Date publication
mars 2016
Journal
Biophysical chemistry
Auteurs
Membres identifiés du Cancéropôle Est :
Dr DELSUC Marc-André
Tous les auteurs :
Viéville JM, Barluenga S, Winssinger N, Delsuc MA
Lien Pubmed
Résumé
Peptide nucleic acids (PNAs) are non-natural oligonucleotides mimics, wherein the phosphoribose backbone has been replaced by a peptidic moiety (N-(2-aminoethyl)glycine). This peptidic backbone lends itself to substitution and the γ-position has proven to yield oligomers with enhanced hybridization properties. In this study, we use Nuclear Magnetic Resonance (NMR) and Circular Dichroism (CD) to explore the properties of the supramolecular duplexes formed by these species. We show that standard Watson-Crick base pair as well as non-standard ones are formed in solution. The duplexes thus formed present marked melting transition temperatures substantially higher than their nucleic acid homologs. Moreover, the presence of a chiral group on the γ-peptidic backbone increases further this transition temperature, leading to very stable duplexes. PNA duplexes with a chiral backbone present a marked chiral secondary structure, observed by CD, and showing a common folding pattern for all studied structures. Nevertheless small differences are observed depending on the details of the nucleobase sequence.
Mots clés
Circular Dichroism, methods, Magnetic Resonance Spectroscopy, methods, Peptide Nucleic Acids, chemistry, Protein Structure, Secondary
Référence
Biophys. Chem.. 2016 Mar;210:9-13