The backbones are one of the important building blocks for synthesizing peptide nucleic acid (PNA) monomer.
PNA is an oligonucleotide analog linked by peptide bond, which uses N - (2-aminoethyl) glycine skeleton instead of sugar phosphate skeleton as a repeating structural unit.
PNA has some physical and chemical properties of polypeptide and nucleic acid due to its unnatural backbones structure, but it is different from polypeptide and nucleic acid molecules. The backbones of polyamides synthesized by PNA have almost no charge, while DNA and RNA molecules have more negative charges due to the strong polarity of polysaccharide and phosphoric acid molecules in the backbones structure. PNA molecules can effectively resist the degradation of nuclease and protease, showing a high degree of biological stability. Even if PNA molecules are incubated with S1 nuclease or DNase I, no degradation will occur. PNA can be chemically modified, for example, it can combine with biotin, fluorescein and other molecules to form marker molecules, or it can combine with DNA, polypeptide and other molecules to form chimeric molecules.
There are three common methods for synthesizing backbones.