Promotion of strand invasion by utilizing entropically-favored PNA

Invasion of peptide nucleic acid (PNA) is important to target a specific site in double-stranded DNA. However, it needs improvement in many ways such as sequence versatility and invasion efficiency. It is here reported that one 10-mer strand of alpha-lysine substituted peptide nucleic acid (PNA) efficiently invades double-stranded DNA (dsDNA) in the presence of single-strand binding protein (SSB) via Watson-Crick rule. According to the thermodynamic parameters in this study, highly efficient invasion was achieved by a favorable entropy change. The importance of preorganization of PNAs for efficient strand invasion is indicated.