title: Hybridization of short complementary PNAs to G-quadruplex forming oligonucleotides: An electrospray mass spectrometry study.
abstract: We investigated the interaction of the short peptide nucleic acid (PNA) strand [acccca]-PNA with oligodeoxynucleotides containing one, two, or four tracts of TGGGGT units. Electrospray ionization mass spectrometry allowed exploring the wide variety of complex stoichiometries that were found to coexist in solution. In water, the PNA strand forms short heteroduplexes with the complementary DNA sequences, but higher-order structures are also found, with PNA(2n).DNA(n) triplex units, culminating in precipitation at very low ionic strength. In the presence of ammonium acetate, there is a competition between PNA.DNA heteroduplex formation and DNA G-quadruplex formation. Heteroduplex formation is favored when the PNA + DNA mixture in ammonium acetate is heated and cooled at room temperature, but not if the PNA is added at room temperature to the preformed G-quadruplex. We also found that the short [acccca]-PNA strand binds to G-quadruplexes.
authors.affiliation: Dipartimento di Chimica delle Sostanze Naturali, Facoltà di Scienze Biotecnologiche, Università di Napoli Federico II, Italy.
authors.forename: Jussara
authors.initials: J
authors.lastname: Amato
authors.forename: Giorgia
authors.initials: G
authors.lastname: Oliviero
authors.forename: Edwin
authors.initials: E
authors.lastname: De Pauw
authors.forename: Valérie
authors.initials: V
authors.lastname: Gabelica
mesh_terms: D002942:Circular Dichroism; D054856:G-Quadruplexes; D009691:Nucleic Acid Denaturation; D009693:Nucleic Acid Hybridization; D009841:Oligonucleotides / Q000737:chemistry* / Q000235:genetics; D009994:Osmolar Concentration; D020135:Peptide Nucleic Acids / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D013696:Temperature
chemical_list: D009841:Oligonucleotides; D020135:Peptide Nucleic Acids