Related Experiment Video
Updated: Aug 8, 2026
13:21
Preparation, Purification, and Characterization of Lanthanide Complexes for Use as Contrast Agents for Magnetic Resonance Imaging
Published on: July 21, 2011
1H NMR studies on lanthanides substituted transferrins
1Department of Chemistry, University of Florence, Italy.
Journal of Inorganic Biochemistry
|May 15, 1991
Summary
Lanthanide(III) ions bind to human serum apotransferrin, showing distinct behaviors at its two metal sites. This study used 1H NMR spectroscopy to reveal these differences in lanthanide binding.
Area of Science:
- Biochemistry
- Biophysical Chemistry
- Spectroscopy
Background:
- Human serum apotransferrin is a key iron-transporting protein.
- Lanthanide ions are sometimes used as probes for metal binding sites in proteins.
- Understanding metal ion interactions with apotransferrin is crucial for biological and medical applications.
Purpose of the Study:
- To investigate the binding of lanthanide(III) ions to human serum apotransferrin.
- To characterize the spectroscopic properties of lanthanide-apotransferrin complexes.
- To explore the differences between the N-terminal and C-terminal metal-binding sites.
Main Methods:
- Proton Nuclear Magnetic Resonance (1H NMR) spectroscopy was employed.
- Isotropically shifted signals were observed for various lanthanide derivatives (Tm, Tb, Yb, Dy).
- Titration experiments with sodium perchlorate were performed to study site-specific interactions.
Main Results:
- Well-resolved, isotropically shifted NMR signals were detected between 100/-100 ppm.
- Significant spectroscopic inequivalence between the two metal binding sites (N-terminal and C-terminal) was observed.
- Distinct behaviors of signals from the C-terminal and N-terminal sites were noted during perchlorate titration.
Conclusions:
- Lanthanide(III) ions exhibit differential binding and spectroscopic characteristics at the two distinct metal-binding sites of human serum apotransferrin.
- 1H NMR spectroscopy is a powerful tool for elucidating metal-protein interactions and site-specific dynamics.
- The findings provide insights into the structural and functional properties of apotransferrin's metal-binding domains.
More Related Videos
Related Concept Videos
03:02Colors and Magnetism
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
01:16Other Nuclides: 31P, 19F, 15N NMR
Many organic, inorganic, and biological molecules contain spin-half nuclei such as nitrogen-15, fluorine-19, and phosphorus-31. As a result, NMR studies of these nuclei have found extensive applications in chemical and biological research.
While fluorine-19 and phosphorous-31 have high natural abundances (100%) and positive gyromagnetic ratios, nitrogen-15 has a low natural abundance and a negative gyromagnetic ratio. However, nitrogen-15 is still preferred over nitrogen-14 (which has a high...
While fluorine-19 and phosphorous-31 have high natural abundances (100%) and positive gyromagnetic ratios, nitrogen-15 has a low natural abundance and a negative gyromagnetic ratio. However, nitrogen-15 is still preferred over nitrogen-14 (which has a high...