title: Vanadium-binding protein excreted by vanadate-reducing bacteria.
abstract: A vanadium-binding protein was isolated from the culture medium of the vanadium-reducing bacterium Pseudomonas isachenkovii by utilizing vanadate as the terminal electron acceptor upon anaerobic respiration. The protein was associated with vanadium at a molar ratio of approximately 1:20. It was purified to homogeneity and separated into three components by treatment with 1 M HCl followed by gel filtration: a protein, a vanadium-binding ligand, and inorganic vanadium. Electron paramagnetic resonance analysis showed that vanadium was associated with the protein in the 4+ oxidation state. The distribution of vanadium within the cell was studied by electron microscopy and x-ray microanalysis of P. isachenkovii cells. The results suggest that vanadium, accumulated in special swells on the surface of the cell membranes, is reduced and excreted to the medium.
authors.affiliation: N. Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow, Russia.
authors.forename: A N
authors.initials: AN
authors.lastname: Antipov
authors.forename: N N
authors.initials: NN
authors.lastname: Lyalikova
authors.forename: N P
authors.initials: NP
authors.lastname: L'vov
mesh_terms: D000693:Anaerobiosis; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000302:isolation & purification / Q000648:ultrastructure; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000302:isolation & purification / Q000648:ultrastructure; D002850:Chromatography, Gel; D004577:Electron Probe Microanalysis; D004578:Electron Spin Resonance Spectroscopy; D008854:Microscopy, Electron; D008970:Molecular Weight; D010084:Oxidation-Reduction; D011549:Pseudomonas / Q000378:metabolism* / Q000648:ultrastructure; D014638:Vanadates / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D014638:Vanadates