Triplex DNA structures in chemical and biochemical analysis

Abstract

The DNA triple helix represents an alternative structure compared to the traditional DNA double helix, owing to the molecule's flexibility to adopt a wide variety of helical structures. Over the past years, the formation and stability of triple helix structures have demonstrated significant applications in multiple scientific disciplines. This work presents a bibliographic research focus on the triplex DNA structure, the factors which determine its stability and its relevance in chemical and biochemical analyses. Additionally, several analytical techniques that enable the detection of triplex DNA structures are also examined, including molecular absorption spectroscopy and electrophoretic techniques. Its structure relies on the specific binding of a triplex-forming oligonucleotide (TFO) to a specific sequence of a double-stranded DNA molecule through Hoogsteen base pairs. This research provides an analysis of the functionality of Hoogsteen and reverse Hoogsteen hydrogen bonds in the stabilization of parallel and antiparallel triplex structures, respectively. For this reason, pH is a critical factor that can enhance or limit the stability and potential applications of the DNA triple helix. One of its most important analytical applications is the detection and recognition of specific biomolecule sequences with high sensitivity and selectivity, as well as the consequent development of advanced biosensors. Furthermore, the use of the triple helix in the fields of nanotechnology and biotechnology through the fabrication of nanodevices has also been examined. Additionally, the DNA triple helix has emerged as a promising platform for gene therapy, providing new avenues for the correction of specific mutations, regulation of gene expression and diagnosis of genetic and cancerous diseases