Lay summary
The research proposal is divided into two, largely independent subjects. The project described in Part A is the direct continuance of my Ph.D. thesis and will be performed in collaboration with Prof. S. Rau, University Erlangen-Nürnberg. Metal-mediated base pairs represent a powerful tool for the site-specific functionalization of nucleic acids with metal ions. Such modified nucleic acids are expected to exhibit enhanced conducting properties which is required for the application of nucleic acids as nanomaterial in electronic devices. Similar to spectroscopic investigations of charge transfer in natural DNA,[1] a corresponding system for metal-modified nucleic acids should be established during this project using two different intercalating RuII-complexes as luminescent probes. First, the influence of the metal ions bound in the metal-mediated base pairs on the properties of the RuII-intercalators will be investigated. Such information is essential to successfully set-up subsequent experiments of photoexcited charge transfer in metal-modified nucleic acids. Part B focuses on the NMR investigation of the metal ion binding ability of the ?-domain of the plant metallothionein (MT) Triticum aestivum (common wheat) Ec-1 and its cyclic analogue. Ec-1 was the first plant MT discovered and up to now the only one with a known three dimensional structure. Its ?-domain, ?-Ec-1, consist of only 25 amino acids and with the NMR solution structure at hand, it is an appropriate system to determine for the first time also the three-dimensional structure of the cyclic MT complement. In addition, NMR spectroscopy with the NMR active nuclei 113Cd, 109Ag, and 199Hg will be accomplish to obtain direct information about the metal ion-to-cysteine connectivities in ?-Ec-1 in dependency on the metal ion. Such verification together with the analogous study of the cyclic component is essential for deeper insights into MT structure and coordination chemistry as well as to open up routes to possible applications in Structural Biology and Pharmaceutical Sciences.