title: (51)V NMR investigation of cell-associated vanadate species in Phycomyces blakesleeanus mycelium.
abstract: (51)V NMR spectroscopy was used for detection and identification of cell-associated vanadate (V(5+)) species after exposure of Phycomyces blakesleeanus mycelium, in exponential phase of growth, to sodium orthovanadate. Complete disappearance of monomer and dimer signals and decreased intensity of the tetramer signal were observed about 40 min after treatment. Simultaneously, a signal at -532 ppm, with increasing intensity, was detected in spectra. The time-dependent rise in this signal was connected to a decrease in the extracellular monomer signal, indicating its transport into the cell. The signal at -532 ppm did not belong to any known simple oxido-vanadate species, nor to a complex with any of the components of experimental medium. This signal was the only one present in spectrum of the mycelium washed 35 min after treatment, and the only one observed in mycelium cultivated on vanadate-contained medium. Therefore, its appearance can be attributed to intracellular complexation, and may represent an important detoxification mechanism of the cell exposed to a physiologically relevant concentration of vanadate. Experiments ((51)V NMR and polarography) performed with Cd-pretreated mycelium (inhibitor of an enzyme responsible for V(5+) reduction) and ferricyanide-preincubated mycelium excluded the possibility of V(5+) tetramer's entry into the cell.
authors.affiliation: Institute for Multidisciplinary Research, Department of Life Sciences, University of Belgrade, Kneza Višeslava 1, 11030 Belgrade, Serbia. Electronic address: mzizic@imsi.rs.
authors.forename: Milan
authors.initials: M
authors.lastname: Žižić
authors.affiliation: Institute of General and Physical Chemistry, NMR Laboratory, Studentski trg 12-16, 11000 Belgrade, Serbia.
authors.forename: Zoran
authors.initials: Z
authors.lastname: Miladinović
authors.affiliation: Institute for Multidisciplinary Research, Department of Life Sciences, University of Belgrade, Kneza Višeslava 1, 11030 Belgrade, Serbia.
authors.forename: Marina
authors.initials: M
authors.lastname: Stanić
authors.affiliation: State University of Novi Pazar, Department of Biomedical Sciences, Vuka Karadžića bb, 36300 Novi Pazar, Serbia.
authors.forename: Mirzeta
authors.initials: M
authors.lastname: Hadžibrahimović
authors.affiliation: University of Belgrade-Faculty of Biology, Department of Physiology and Biophysics, Studentski trg 16, 11000 Belgrade, Serbia.
authors.forename: Miroslav
authors.initials: M
authors.lastname: Živić
authors.affiliation: Institute of General and Physical Chemistry, NMR Laboratory, Studentski trg 12-16, 11000 Belgrade, Serbia.
authors.forename: Joanna
authors.initials: J
authors.lastname: Zakrzewska
mesh_terms: D008658:Inactivation, Metabolic; D009682:Magnetic Resonance Spectroscopy; D025282:Mycelium / Q000737:chemistry*; D010800:Phycomyces / Q000737:chemistry* / Q000254:growth & development / Q000378:metabolism*; D014638:Vanadates / Q000032:analysis / Q000378:metabolism*
chemical_list: D014638:Vanadates
keywords: (51)V NMR; Fungi; Phycomyces blakesleeanus; Vanadate