The binding of plutonium to serum proteins in vitro.

This study investigates how the radioactive element plutonium binds to proteins found in horse serum in a laboratory setting. The primary finding is that in horse serum, as in other mammal’s blood serum, plutonium chiefly binds to the transferrin component of the protein group called beta1-globulins.

Research Methodology

The researchers used two main techniques to explore the interaction between plutonium and horse serum proteins, which were electrophoresis on cellulose acetate and gel filtration.

• Electrophoresis on cellulose acetate: This is a technique used to separate proteins based on their size, shape, and charge. In this case, it was used to observe where the plutonium was binding on the proteins.
• Gel filtration: Also known as size exclusion chromatography, this method also separates proteins, but it does so according to their size. The researchers utilized this method to verify the results obtained from the electrophoresis.

Key Findings

The main findings of this study can be broken down into several significant points:

• The plutonium in the horse serum principally binds with the transferrin component of the beta1-globulins proteins.
• Creating the plutonium-transferrin complex requires the presence of HCO3-, bicarbonate ions. This suggests that bicarbonate ions play a role in the binding process.
• Plutonium can be pushed out of the complex if there is an excess amount of iron. This implies that the binding sites for iron and plutonium could be similar, or indeed the same.
• The stability of the plutonium-transferrin complex is less than that of the iron-transferrin complex. However, the plutonium can only be removed from the complex by the use of citrate or other stronger chelating agents, revealing the substantial binding strength of the plutonium to the transferrin protein.

In simplifying this process, the researchers have found that plutonium binds with the transferrin, a protein in horse serum, in a similar way it binds with other mammalian blood serum proteins.