1. Utility of peptide nucleic acids in biosensor development
Laurie Connell University of Maine Orono Maine
What are Peptide Nucleic Acids (PNA’s)?
PNA probe signals can be more specific and stronger than DNA probes.
PNA’s have neutral backbones
DNA or RNA analog with a protein backbone and purine (A,G) or pyrimidine (T,C) attached through methylene carbonyl linkages. Unlike DNA and most DNA analogs they contain no sugar or phosphate groups
0.5 1
1.5
450nm
tri-flur
bi-flur
LC01005 bi-flur
From BPI
Bind in a wide range of salt concentrations
Can enter cells more rapidly
Stronger binding between PNA/DNA than DNA/DNA
PNA/DNA duplex mismatches more destabilizing than DNA/DNA duplexes
Neutral backbone increases rate of hybridization
Sugar backbone
Peptide backbone
An example of probe binding comparing a bi-labeled PNA probes(Red) to the analogous bi-labeled DNA probe (blue) and a tri-labeled DNA probes (green) in a semi- automated sandwich hybridization format. The probes in this case used the red tide alga Alexandrium as its target.
Additionally
PNA’s are not targets of natural enzyme destruction
PNA probes are smaller than analogous DNA probes
PNA’s strictly conform to Watson-Crick base paring rules