Introducing metallic ions within a DNA molecule will have many uses in bio- and nanotechnology

(Nanowerk News) Researchers from the University of Granada have proven, for the first time, that introducing slight chemical modifications in DNA molecules may allow to introduce metallic ions in it, keeping its double-stranded structure and molecular recognition properties (for other DNA molecules, enzymes, proteins, etc.).
This breakthrough may allow the use of hybrid metal-DNA molecules for various applications in the fields of biotechnology and biomedicine, given that DNA structure remains practically unaltered and the metallic ions may bring new properties to DNA molecules, such as fluorescence, conductivity, magnetism or catalytic properties.
The research work, published in the renowned chemistry journal Angewandte Chemie ("Highly Stable Double-Stranded DNA Containing Sequential Silver(I)-Mediated 7-Deazaadenine/Thymine Watson–Crick Base Pairs"), has been carried out in the department of Inorganic Chemistry at the UGR, managed by lead researcher Miguel A. Galindo Cuesta (hired under the UGR vice-chancellorship Program for Research and Transfer), and funded by the European project Marie Curie and the Andalusian Regional Government.
From left to right: José M. Méndez, Miguel A. Galindo and Juan M. Salas
The research team from the University of Granada who have worked in this project. From left to right: José M. Méndez, Miguel A. Galindo and Juan M. Salas.
The formation of these metal-DNA hybrids has been achieved carrying out slight chemical modifications in some of the DNA molecules' components, in particular, replacing adenine units with 7-deazaadenine units, which allows to keep their auto-recognition properties unaltered (by means of Watson-Crick hydrogen bonding) and facilitates the incorporation of metallic ions within.
DNA structure and some of its properties were described by James D. Watson and Francis Crick (which were awarded the Nobel Prize in 1953), that's why the specific bonds which take place within are given their names.
The research team from the UGR has managed to transform said Watson-Crick bondings into similar bondings, but carried out by silver metallic ions. This originates hybrid, highly stable DNA molecules capable of holding metallic ions in specific and controlled positions within the DNA molecules.
This is a breakthrough given that, for the first time, we can obtain big DNA molecules which keep their natural properties (base complementarity) unaltered, and whose metallic ions are distributed along the whole DNA molecule.
As professor Miguel A. Galindo Cuesta explains, "until now, the international scientific community had only managed to introduce a small amount of metallic ions in some sections of the DNA structure using sophisticated chemical alterations which made it lose its natural properties, thus limiting possible applications".
The research team is currently expanding this strategy in collaboration with Javier Martínez from the Centre for Genomics and Oncological Research (GENyO), in order to prepare metal-DNA, nanometric systems with well-defined structures by using enzymatic, DNA replication methods. The goal is to develop metal-DNA hybrids with potential biotechnological applications aimed at medicine and nanotechnology.
Source: University of Granada