Nucleic Acid Aptamers
Aptamers are short single-stranded nucleic acid oligomers (DNA or RNA) capable of folding into highly organised, complex structures enabling ligation to molecular targets with high affinity. They can have sequence-dependent structures, characterised by stems, loops, bulges, hairpins, pseudoknots, triplexes, or quadruplexes.
These simple secondary structures can fold further to give tertiary structures, enabling aptamers to form complementary shapes wrapping around all or part of their target (small molecules) or fit snugly into clefts and gaps within the surface of much larger targets.
This structural complementarity facilitates formation of electrostatic interactions or hydrogen bonds between the aptamer and its target, as well as stacking interactions between aromatic compounds and the nucleobases. This ability to fold into or around a target means that it should be theoretically possible to select specific aptamers to almost any given target.
The benefit of an Aptamer (nucleic acid aptamer) is its ability to fold into or around a target meaning an aptamer can bind to almost any given target.
Many people describe aptamers as synthetic antibodies. Certainly, in some of the opportunities offered there is a comparison. In the end, and why the scientific community are so switched on to them, is because of the benefits.
Aptamers have been successfully raised to almost every type of Organic and some Inorganic compounds, including:
- Inorganic molecules
- Small organic molecules
- Peptides & proteins
- Complex targets – cells/viruses/microorganisms/tissue sections etc.
The Development of the Technology
The development of the Aptamer technology stems from the understanding that nucleic acids are not simply carriers of genetic information. They are also capable of carrying out complex molecular interactions and are involved in many biological processes including:
- Ribosome binding sites