title: Complexation of U(VI) with highly phosphorylated protein, phosvitin A vibrational spectroscopic approach.
abstract: The complexation of uranium(VI) to variant functional groups of the highly phosphorylated protein phosvitin in aqueous solution was investigated by attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy. For the verification of the affinity of the actinyl ions to carboxyl and phosphate groups of the amino acid side chains, samples with different phosphate to uranium(VI) (P/U) ratios were investigated under denaturing conditions as well as in aqueous medium. From a comparative study with other heavy metal ions, i.e. Ba(2+) and Pb(2+), a strong coordination of U(VI) to carboxyl and phosphoryl groups can be derived. Furthermore, with increasing P/U ratios, a preferential binding of U(VI) to phosphoryl groups is indicated by the spectra of the batch samples. These findings are confirmed by spectra of aqueous U(VI)-phosvitin complexes reflecting an explicit coordination of the uranyl ions to phosphate groups at a high P/U ratio. Our study provides a deeper insight into the molecular interactions between actinyl ions and protein, and can be conferred to other basic biomolecules such as polysaccharides and nucleic acids.
authors.affiliation: Institute of Radiochemistry, Forschungszentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden, Germany.
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.forename: Johannes
authors.initials: J
authors.lastname: Raff
authors.forename: Astrid
authors.initials: A
authors.lastname: Barkleit
authors.forename: Gert
authors.initials: G
authors.lastname: Bernhard
authors.forename: Harald
authors.initials: H
authors.lastname: Foerstendorf
mesh_terms: D001464:Barium; D001665:Binding Sites; D007854:Lead; D010750:Phosphoproteins / Q000737:chemistry* / Q000378:metabolism; D010774:Phosvitin / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D011489:Protein Denaturation; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D014501:Uranium / Q000737:chemistry*
chemical_list: D010750:Phosphoproteins; D001464:Barium; D007854:Lead; D014501:Uranium; D010774:Phosvitin