title: Metal ion selectivity of the vanadium(V)-reductase Vanabin2.
abstract: In a previous study, Vanabin2, a member of a family of V(IV)-binding proteins, or Vanabins, was shown to act as a V(V)-reductase. The current study assesses the ability of Vanabin2 to reduce various transition metal ions in vitro. An NADPH-coupled oxidation assay yielded no evidence of reduction activity with the hexavalent transition metal anions, Mo(VI)O4(2-) and W(VI)O4(2-), or with three divalent cations, Mn(II), Ni(II), and Co(II). Although Cu(II) is readily reduced by glutathione and is gradually oxidized in air, this process was not affected by the presence of Vanabin2. In the experiments conducted thus far, Vanabin2 acts only as a V(V)-reductase. This high selectivity may account for the metal ion selectivity of vanadium accumulation in ascidians.
authors: Molecular Physiology Laboratory, Department of Biological Science, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan.
authors: Hiroki
authors: H
authors: Kitayama
authors: Sohei
authors: S
authors: Yamamoto
authors: Hitoshi
authors: H
authors: Michibata
authors: Tatsuya
authors: T
authors: Ueki
mesh_terms: D000818:Animals; D007700:Kinetics; D019216:Metals, Heavy / Q000737:chemistry / Q000378:metabolism*; D009249:NADP / Q000737:chemistry / Q000378:metabolism; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000737:chemistry / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D014561:Urochordata / Q000201:enzymology
chemical_list: D019216:Metals, Heavy; D011994:Recombinant Proteins; D009249:NADP; D010088:Oxidoreductases