Related Experiment Video
Updated: Dec 8, 2025
12:22
Speciation and Bioavailability Measurements of Environmental Plutonium Using Diffusion in Thin Films
Published on: November 9, 2015
11.7K
How Does Iron Storage Protein Ferritin Interact with Plutonium (and Thorium)?
Cyril Zurita1, Satoru Tsushima2,3, Carole Bresson4
1CNRS, Institut de Chimie de Nice, Université Côte d'Azur, 06108, Nice, France.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|September 21, 2020
Summary
Early actinides like thorium and plutonium interact with ferritin, the iron storage protein, primarily binding to the protein ring rather than the core. This finding is crucial for understanding actinide toxicology in living organisms.
Area of Science:
- Biochemistry
- Toxicology
- Nuclear Science
Background:
- Actinide element contamination in organisms is a persistent concern with limited understanding.
- Ferritin is a key protein for iron storage and regulation in many organisms.
- Ferritin's structure comprises a protein shell and a central ferrihydrite core.
Purpose of the Study:
- To investigate the interaction and storage of early actinides (thorium and plutonium) by ferritin at physiological pH.
- To compare the binding behavior of actinides with iron within the ferritin protein.
- To elucidate the molecular mechanisms underlying actinide-ferritin interactions.
Main Methods:
- Loading experiments to determine actinide saturation levels in ferritin.
- Spectroscopic techniques including spectrophotometry, infrared spectroscopy, and X-ray absorption spectroscopy (XAS).
- Molecular dynamics (MD) simulations for structural modeling.
Main Results:
- Thorium (ThIV) saturates ferritin similarly to iron (Fe), with up to 2840 Th atoms per ferritin molecule.
- Spectroscopic and MD data indicate ThIV and Plutonium (PuIV) complex primarily with the ferritin protein ring, not the ferrihydrite core.
- XAS data revealed no iron neighbors in the thorium and plutonium coordination spheres.
- Coordination spheres are influenced by amino acid carboxylates and potentially carbonate anions.
Conclusions:
- Ferritin binds early actinides (ThIV, PuIV) mainly on its protein shell, distinct from its iron-storage mechanism.
- This molecular-level understanding of actinide-ferritin interactions is vital for nuclear toxicology.
- The findings provide a foundation for assessing the biological impact of actinide contamination.
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