Template-Assembled Synthetic G-Quadruplex (TASQ): A Useful System for Investigating the Interactions of Ligands with Constrained Quadruplex Topologies
A new biomolecular device for investigating the interactions of ligands with constrained DNA quadruplex topologies, using surface plasmon resonance (SPR), is reported. Biomolecular systems containing an intermolecular-like G-quadruplex motif 1 (parallel G-quadruplex conformation), an intramolecular G-quadruplex 2, and a duplex DNA 3 have been designed and developed. The method is based on the concept of template-assembled synthetic G-quadruplex (TASQ), whereby quadruplex DNA structures are assembled on a template that allows precise control of the parallel G-quadruplex conformation. Various known G-quadruplex ligands have been used to investigate the affinities of ligands for intermolecular…
Prefolded Synthetic G-Quartets Display Enhanced Bioinspired Properties
International audience; A water-soluble template-assembled synthetic G-quartet (TASQ) based on the use of a macrocyclodecapeptide scaffold was designed to display stable intramolecular folds alone in solution. The preformation of the guanine quartet, demonstrated by NMR and CD investigations, results in enhanced peroxidase-type biocatalytic activities and improved quadruplex-interacting properties. Comparison of its DNAzyme-boosting properties with the ones of previously published TASQ revealed that, nowadays, it is the best DNAzyme-boosting agent.
Closer to nature: an ATP-driven bioinspired catalytic oxidation process
The capability of DNA to acquire enzyme-like properties has led to the emergence of the so-called DNAzyme field; herein, we take a further leap along this nature-inspired road, demonstrating that a template assembled synthetic G-quartet (TASQ) can act as a pre-catalyst for catalytic peroxidase-mimicking oxidation reactions, whatever its nature (guanine or guanosine-based G-quartets), in an ATP-dependent manner, thereby bringing this bioinspired TASQzyme process even closer to nature.
Surface-immobilized DNAzyme-type biocatalysis
The structure of the double helix of deoxyribonucleic acid (DNA, also called duplex-DNA) was elucidated sixty years ago by Watson, Crick, Wilkins and Franklin. Since then, DNA has continued to hold a fascination for researchers in diverse fields including medicine and nanobiotechnology. Nature has indeed excelled in diversifying the use of DNA: beyond its canonical role of repository of genetic information, DNA could also act as a nanofactory able to perform some complex catalytic tasks in an enzyme-mimicking manner. The catalytic capability of DNA was termed DNAzyme; in this context, a peculiar DNA structure, a quadruple helix also named quadruplex-DNA, has recently garnered considerable i…