Interactions between oligonucleotide secondary structures and potential ligands

Oligonucleotide analogues (ODNs) are biomolecules with great scientific potential due to their remarkable properties (higher bioavailability, target affinity, stability and resistance to nuclease degradation). They can therefore be used as nanoprobes and biosensors, but also for the development of new materials in the field of nanotechnology. ODNs and their analogues can adopt several secondary structures that play an important role in biology, biotechnology and nanotechnology. In particular, ODNs rich in guanine can adopt secondary structures called G-quadruplexes, which are also very interesting from a diagnostic and therapeutic point of view. In the human genome, G-quadruplexes are found in regions of genes of high regulatory importance (such as enhancers, promoters and oncogenes). Stabilisation and destabilisation of these secondary structures have been shown to influence the onset of disease. There is a field of research investigating the interactions between small molecules and DNA secondary structures, including G-quadruplexes. In this paper we focus on the interactions between G-quadruplexes and modified porphyrins, a class of macrocyclic compounds that play a very important role in the metabolism of living organisms.