Related Experiment Video
Updated: Dec 28, 2025
05:37
Single-Molecule Fluorescence Visualization of DNA Polymerase Dynamics at G-Quadruplexes
Published on: April 4, 2025
1.1K
Heteroleptic Coordination Environments in Metal-Mediated DNA G-Quadruplexes
Philip M Punt1, Lukas M Stratmann1, Sinem Sevim1
1Faculty of Chemistry and Chemical Biology, TU Dortmund University, Dortmund, Germany.
Frontiers in Chemistry
|February 18, 2020
Summary
Researchers created novel DNA G-quadruplexes with imidazole and benzoate ligands to mimic metalloenzymes. These structures successfully bind copper, nickel, and zinc ions, advancing the design of functional metallo-DNAzymes.
Area of Science:
- Bioinorganic Chemistry
- DNA Nanotechnology
- Supramolecular Chemistry
Background:
- Metalloenzymes are vital for numerous biological processes, with metal centers in conserved coordination environments.
- Synthesizing model compounds with defined metal sites is key to understanding and mimicking metalloenzyme function.
- Previous work established DNA G-quadruplexes as scaffolds for homoleptic metal coordination environments using imidazole ligandosides (L).
Purpose of the Study:
- To develop more complex, heteroleptic coordination environments within DNA G-quadruplex scaffolds.
- To investigate the binding capabilities of these novel DNA structures with transition metal ions.
- To explore the potential for creating functional metallo-DNAzymes.
Main Methods:
- Design and synthesis of modified DNA G-quadruplexes incorporating both imidazole (L) and benzoate (L') ligandosides.
- Analysis of G-quadruplex folding and stability using thermal denaturation experiments (Tm).
- Investigation of metal ion complexation (CuII, NiII, ZnII) within the heteroleptic DNA structures.
Main Results:
- Modified G-quadruplexes with L' ligands showed destabilization (lower Tm).
- Heteroleptic G-quadruplexes (containing both L and L') successfully complexed CuII, NiII, and ZnII.
- CuII complexation resulted in significant stabilization of the G-quadruplex structure (up to +34°C).
Conclusions:
- The modular DNA G-quadruplex system can be expanded to create complex heteroleptic coordination environments.
- These DNA scaffolds can selectively bind specific transition metal ions, demonstrating tunable properties.
- This work represents a significant advancement towards designing functional metallo-DNAzymes using DNA scaffolds.
Related Concept Videos
02:51Metal-Ligand Bonds
23.5K
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
23.5K
02:42Valence Bond Theory
10.9K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
10.9K
02:57Coordination Number and Geometry
18.5K
For transition metal complexes, the coordination number determines the geometry around the central metal ion. Table 1 compares coordination numbers to molecular geometry. The most common structures of the complexes in coordination compounds are octahedral, tetrahedral, and square planar.
18.5K
02:52Stereoisomerism
13.7K
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
13.7K
01:19Complexation Equilibria: The Chelate Effect
1.0K
In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen...
1.0K
01:22EDTA: Chemistry and Properties
3.1K
Polydentate ligands are most widely used in complexometric titrations because they form more stable complexes with the metal ions than mono- or bidentate ligands due to the chelate effect. Examples of polydentate ligands are ethylenediaminetetraacetic acid (EDTA), crown ethers, and cryptands. The most important feature of optimal polydentate ligands is the ability to form 1:1 complexes in a single-step process. Amino carboxylic acid derivatives are frequently used as complexing agents. EDTA is...
3.1K