Extended DNA-Recognition Repertoire of Peptide Nucleic Acid (PNA): PNA-dsDNA triplex formed with cytosine-rich homopyrimidine PNA
Journal article, 1997

Peptide nucleic acid (PNA) is an oligonucleotide mimic in which the backbone of DNA has been replaced by a pseudopeptide. Thymine-rich homopyrimidine PNA oligomers have been found to recognize double-stranded DNA targets by displacement of the pyrimidine DNA strand and forming an internal Watson-Crick-Hoogsteen base-paired PNA(pyr)-DNA(pu)-PNA(pyr) tripler. We here show that cytosine-rich homopyrimidine PNA sequences instead add to double-stranded polynucleotide targets as Hoogsteen strands forming PNA(pyr)-DNA(pu)-DNA(pyr) triplexes. Furthermore, PNA strands with homopurine or alternating thymine-guanine sequences are shown to invade their respective DNA targets by displacing the identical DNA strands of the polynucleotides and forming new PNA-DNA duplexes. These results indicate distinct mechanistic variations as to how PNA interacts with a DNA target depending on choice of nucleobases, which could be of importance for future design of gene-specific diagnostic or therapeutic agents.


Pernilla Wittung

Department of Physical Chemistry

P. Nielsen

Bengt Nordén

Department of Physical Chemistry


0006-2960 (ISSN) 1520-4995 (eISSN)

Vol. 36 26 7973-7979

Areas of Advance

Nanoscience and Nanotechnology (SO 2010-2017, EI 2018-)


Life Science Engineering (2010-2018)

Materials Science

Subject Categories

Physical Chemistry


Basic sciences



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