Rapidly reversible DNA-quadruplex-based molecular capture system
A specific and rapidly reversible system for single molecule capture employing magnesium-dependent DNA quadruplex structures.
Research and medical technology are increasingly dependent on single molecule capture and analysis. The current gold standard for non-covalent immobilization is streptavidin-biotin (STV-B). Although widely used, the biotin component in the interaction is resistant to dissociation, thus requiring harsh and potentially damaging conditions in order to release the biotinylated protein or oligonucleotide following capture. In addition, the process is irreversible and can have non-specificity issues in biotin-rich tissues. Finally, the process is time consuming as it is incapable of multiplexing and the shelf life is limited.
Dr. Kankia and colleagues at Ohio State have developed a novel method of coupling nucleic acids using a quadruplex-and-Mg2+ connection (QMC). This new technology is based upon the naturally occurring and extraordinarily stable tetrahelical DNA structures known as G-quadruplexes. Structural and biochemical modifications introduced into the DNA quadruplex sequence have yielded their QMC system, which consists of a target and capture component exhibiting an affinity similar to that observed for the STV-B capture system. However, the QMC target-capture molecular interaction is rapid and fully reversed by removal of Mg2+ from the reaction system. The QMC quadruplex structures represent a significant advancement in the field of biotechnology by providing an alternative and more broadly applicable single molecule capture technology with the potential to replace and improve upon the currently used streptavidin-biotin system.