Related Experiment Video
Updated: May 17, 2026

CD Spectroscopy to Study DNA-Protein Interactions
Published on: February 10, 2022
Spectroscopic studies on the binding of holmium-1,10-phenanthroline complex with DNA
Sona Niroomand1, Mozhgan Khorasani-Motlagh, Meissam Noroozifar
1Department of Chemistry, University of Sistan & Baluchestan, P.O. Box 98155-147, Zahedan, Iran.
Abstract:
Fluorescence and absorption spectroscopy, circular dichroism (CD) as well as viscosity experiment have been used to characterize the DNA binding of [Ho(Phen)(2)Cl(3)]·H(2)O, where phen stand for 1,10-phanathroline. This complex exhibits the marked decrease in the emission intensity and some hypochromism in UV-Vis spectrum in the presence of DNA. For characterization of the binding mode between the Ho(III) complex and DNA various procedures such as: absorption and emission titration and EB quenching experiments, viscosity measurements, CD study, iodide quenching assay, salt effect and thermodynamical investigation are used. The intrinsic binding constant of [Ho(Phen)(2)Cl(3)]·H(2)O with DNA is calculated by UV-Vis and florescence spectroscopy. The value of binding constants in 296, 299 and 303 are 1.99 ± 0.07 × 10(4), 1.07 ± 0.09 × 10(4) and 0.84 ± 0.06 × 10(4), respectively. The thermodynamic studies show that the reaction is entropically driven. The above-mentioned physical measurements indicate that the Ho(III) complex binds to fish salmon DNA, presumably via groove binding mode.
Related Concept Videos
2D NMR: Overview of Heteronuclear Correlation Techniques
2D NMR: Heteronuclear Single-Quantum Correlation Spectroscopy (HSQC)
Labeling DNA Probes
Radioisotopes, fluorophores, or small molecule binding partners like biotin or digoxigenin, are the most widely used reporter tags for labeling DNA probes. These labels can be attached to the probe DNA molecule via...
¹H NMR: Interpreting Distorted and Overlapping Signals
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or...
Single-Strand DNA Binding Proteins
¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
