DNA with metal-mediated base pairs

Metal-mediated base pairs represent a prominent means for the site-specific incorporation of metal-based functionality into nucleic acids. In metal-mediated base pairs, the metal ions are located inside the double helix. This unusual localization is accomplished by using artificial base surrogates capable of binding metal ions, hence by a formal substitution of hydrogen bonds within a base pair by coordinate bonds. We are designing artificial nucleobases to be used in is this kind of bio-inspired self-assembling array of metal ions. Moreover, we are developing applications for nucleic acids with metal-mediated base pairs.

Stabilisation of parallel-stranded DNA with metals and metal complexes

Parallel-stranded (ps) DNA is an emerging new feature of DNA structure. It is usually characterised by the occurrence of reverse Watson Crick base pairs or homo base pairs and mostly displays a trans-orientation of the glycosidic bonds. Only few examples are known with Hoogsteen base pairing, which at the same time provide the only examples with a cisoid arrangement of the glycosidic bonds. We are interested in factors stabilizing ps DNA, and in particular in the question whether metal-mediated base pairs are capable of stabilizing ps DNA.

Stabilization of quadruplex DNA by transition metal complexes

In addition to our work on the site-specific functionalization of nucleic acids, we are developing metal complexes capable of selectively targeting guanine quadruplex DNA as a further central pillar of our bioinorganic research. Such metal complexes are expected to serve as metallo-drugs with a new mode of action. Metal complexes capable of selectively stabilizing quadruple helices are in many cases planar, i.e. they share this property with our metal-mediated base pairs. As a result, most model complexes for metal-mediated base pairs are potential quadruplex binders.