title: Nature of cerium(III)- and lanthanum(III)-induced aggregation of human erythrocyte membrane proteins.
abstract: To clarify the nature of the aggregation of membrane proteins (MP) induced by lanthanide cations (Lns), the interaction of cerium(III) (Ce3+) and lanthanum(III)(La3+) with erythrocyte membrane proteins was studied by means of SDS-PAGE, light scattering measurement, fluorescence, CD and FTIR spectra. The results showed that Ce3+ and La3+ induce protein aggregation not only by Lns non-covalent binding and cross-linking, but also by oxidative cross-linking through disulfide bond formation. As demonstrated by intrinsic fluorescence, CD and FTIR spectra studies, the aggregation was accompanied by the conformation changes with tryptophane residues exposing to more hydrophobic environment and the decreasing alpha-helix and beta-sheet contents. By stopped-flow studies, protein aggregation was shown to be a slow change, which is initiated by rapid Lns binding and then followed by subsequent conformational changes.
authors.affiliation: Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, China.
authors.forename: X
authors.initials: X
authors.lastname: Du
authors.forename: T
authors.initials: T
authors.lastname: Zhang
authors.forename: R
authors.initials: R
authors.lastname: Li
authors.forename: K
authors.initials: K
authors.lastname: Wang
mesh_terms: D001798:Blood Proteins / Q000737:chemistry / Q000187:drug effects*; D002563:Cerium / Q000633:toxicity*; D002942:Circular Dichroism; D003432:Cross-Linking Reagents / Q000633:toxicity; D004492:Edetic Acid / Q000494:pharmacology; D004910:Erythrocyte Membrane / Q000737:chemistry / Q000187:drug effects*; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D007811:Lanthanum / Q000633:toxicity*; D008027:Light; D008565:Membrane Proteins / Q000097:blood / Q000737:chemistry / Q000187:drug effects*; D010084:Oxidation-Reduction; D011487:Protein Conformation / Q000187:drug effects; D017433:Protein Structure, Secondary / Q000187:drug effects; D012542:Scattering, Radiation; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D001798:Blood Proteins; D003432:Cross-Linking Reagents; D008565:Membrane Proteins; D002563:Cerium; D007811:Lanthanum; D004492:Edetic Acid