Structural Environment and Stability of the Complexes Formed Between Calmodulin and Actinyl Ions
Résumé
The interaction site of neptunyl with the calmodulin and electronic density. The complexation of uranium(VI) and neptunium(V) was investigated with recombinant one-site variant of the calmodulin N-terminal domain, denoted CaM-WT. The combination of experimental results (UV−vis and extended X-ray absorption fine structure spectroscopy) and density functional theory (DFT) calculations revealed that the coordination sphere of uranyl is pH dependent, while netunyl’s stays the same at every pH studied. The DFT calculations showed that at physiological pH the complex formed between the protein and the netunyl is more stable than the one formed with uranyl.