Project

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A: Photoactivated charge transfer in metal-modified nucleic acids B: NMR study on the ?-domain of the plant metallothionein Ec-1 and its cyclic analogue

Applicant Johannsen Silke
Number 134160
Funding scheme Marie Heim-Voegtlin grants
Research institution Institut für Chemie Universität Zürich
Institution of higher education University of Zurich - ZH
Main discipline Inorganic Chemistry
Start/End 01.02.2011 - 31.01.2013
Approved amount 207'755.00
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All Disciplines (2)

Discipline
Inorganic Chemistry
Biophysics

Keywords (6)

metal-modified nucleic acids; photoluminescence; charge transfer; nanomaterial; metallothioneins; metal NMR spectroscopy

Lay Summary (English)

Lead
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.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
NMR Spectroscopy in Bioinorganic Chemistry
Donghi Daniela, Johannsen Silke, Sigel Roland K. O., Freisinger Eva (2012), NMR Spectroscopy in Bioinorganic Chemistry, in CHIMIA, 66(10), 791-797.
Synthesis and Acid?Base Properties of an Imidazole-Containing Nucleotide Analog, 1-(2'-Deoxy-ss-D-ribofuranosyl)imidazole 5'-Monophosphate (dImMP2-)
Megger Nicole, Johannsen Silke, Mueller Jens, Sigel Roland K. O. (2012), Synthesis and Acid?Base Properties of an Imidazole-Containing Nucleotide Analog, 1-(2'-Deoxy-ss-D-ribofuranosyl)imidazole 5'-Monophosphate (dImMP2-), in CHEMISTRY & BIODIVERSITY, 9(9), 2050-2063.
Intrinsic Acid-Base Properties of a Hexa-2'-deoxynucleoside Pentaphosphate, d(ApGpGpCpCpT). Neighboring Effects and Isomeric Equilibria
Domínguez-Martín Alicia, Johannsen Silke, Sigel Astrid, Operschall Bert P., Song Bin, Sigel Helmut, Okruszek Andrzej, González-Pérez Josefa María, Niclós-Gutiérrez Juan, Sigel Roland K. O., Intrinsic Acid-Base Properties of a Hexa-2'-deoxynucleoside Pentaphosphate, d(ApGpGpCpCpT). Neighboring Effects and Isomeric Equilibria, in Chemistry-A European Journal.

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
SCS Fall Meeting 13.09.2012 Zürich
International Conference on Magnetic Resonance in Biological Systems 19.08.2012 Lyon


Associated projects

Number Title Start Funding scheme
112708 Molecular Wires Based on Metal-Modified Oligonucleotides 01.04.2006 ERA-Chemistry
144964 Upgrade of the UZH NMR Core Facility 01.12.2012 R'EQUIP

Abstract

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.
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