PNA (Peptide Nucleic Acid) an artificially created DNA analogue was invented by Drs. Nielsen, Egholm, Berg, and Buchardt in 1991. The phosphate ribose ring of DNA was replaced with the polyamide backbone in PNA. Despite a radical structural change, PNA is capable of sequence-specific binding in a helix form to its complementary DNA or RNA sequence. Due to its superior binding affinity and chemical/biological stability, PNA has been widely applied in the field of biology.
■ PNA (peptide nucleic acid) is an artificially created nucleic acid replaced with polyamide backbone of
N-(2-aminoethyl)glycine.
■ PNA strongly binds to its complementary DNA or RNA sequence by Watson-Crick base pairing.
■ PNA has high specificity, sensitivity and stability as molecular probes for molecular diagnostics
and antisense drugs.
Criteria
PNA
DNA
Hybridization affinity with DNA
At least 1℃ higher Tm per base
-
Hybridization rate with DNA
100-5,000 times faster
-
Salt concentration for hybridization
Independent
Dependent
Tm for each single mismatch
Lowering 15℃
Lowering 10℃
Chemical stability
Stable
Unstable or moderate
Probe length
13-18mer
25-30mer
Biological stability
Stable to nuclease and protease
Degradation by nuclease
Thermal stability
Good
Moderate
1
Hyunil Lee et al. Peptide Nucleic Acid Synthesis by Novel Amide Formation.
Organic Letters 2007;9(17):3291-3293.