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Tris (phenanthroline) metal complexes: probes for DNA helicity
1Department of Chemistry, Columbia University, New York, New York 10027.
Journal of Biomolecular Structure & Dynamics
|December 1, 1983
Summary
Chiral metal complexes show stereo-selective DNA binding, differentiating between DNA forms. This selectivity allows chiral complexes to act as probes for distinguishing DNA helices.
Area of Science:
- Coordination Chemistry
- Molecular Biology
- Biophysical Chemistry
Background:
- Chiral tris(phenanthroline) metal complexes exhibit intercalative binding to DNA.
- Enantiomeric selectivity in binding arises from steric interactions between ligands and the DNA phosphate backbone.
Purpose of the Study:
- To investigate the stereo-selective binding of chiral tris(phenanthroline) metal complexes to DNA.
- To explore the use of these complexes as chemical probes for distinguishing DNA helices.
Main Methods:
- Gel electrophoretic assays for helical unwinding.
- Optical enrichment studies using equilibrium dialysis.
- Luminescence titrations with separated enantiomers of (phen)3Ru2+ and RuDIP.
Main Results:
- The delta isomer of (phen)3Ru2+ preferentially binds to right-handed DNA duplexes.
- Chiral discrimination is influenced by DNA helical asymmetry.
- RuDIP isomers bind to Z-DNA, but lambda-RuDIP is precluded from binding to B-DNA.
Conclusions:
- Chiral tris(phenanthroline) metal complexes demonstrate enantiomeric selectivity in DNA binding.
- These complexes can serve as effective chemical probes to differentiate between left- and right-handed DNA helices in solution.
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