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Baysse C, De Vos D, Naudet Y, Vandermonde A, Ochsner U, Meyer JM, Budzikiewicz H, Schäfer M, Fuchs R, Cornelis P. Vanadium interferes with siderophore-mediated iron uptake in Pseudomonas aeruginosa. MICROBIOLOGY (READING, ENGLAND) 2000; 146 ( Pt 10):2425-2434. [PMID: 11021919 DOI: 10.1099/00221287-146-10-2425] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Vanadium is a metal that under physiological conditions can exist in two oxidation states, V(IV) (vanadyl ion) and V(V) (vanadate ion). Here, it was demonstrated that both ions can form complexes with siderophores. Pseudomonas aeruginosa produces two siderophores under iron-limiting conditions, pyoverdine (PVD) and pyochelin (PCH). Vanadyl sulfate, at a concentration of 1-2 mM, strongly inhibited growth of P. aeruginosa PAO1, especially under conditions of severe iron limitation imposed by the presence of non-utilizable Fe(III) chelators. PVD-deficient mutants were more sensitive to vanadium than the wild-type, but addition of PVD did not stimulate their growth. Conversely, PCH-negative mutants were more resistant to vanadium than the wild-type strain. Both siderophores could bind and form complexes with vanadium after incubation with vanadyl sulfate (1:1, in the case of PVD; 2:1, in the case of PCH). Although only one complex with PVD, V(IV)-PVD, was found, both V(IV)- and V(V)-PCH were detected. V-PCH, but not V-PVD, caused strong growth reduction, resulting in a prolonged lag phase. Exposure of PAO1 cells to vanadium induced resistance to the superoxide-generating compound paraquat, and conversely, exposure to paraquat increased resistance to V(IV). Superoxide dismutase (SOD) activity of cells grown in the presence of V(IV) was augmented by a factor of two. Mutants deficient in the production of Fe-SOD (SodB) were particularly sensitive to vanadium, whilst sodA mutants deficient for Mn-SOD were only marginally affected. In conclusion, it is suggested that V-PCH catalyses a Fenton-type reaction whereby the toxic superoxide anion O(2)- is generated, and that vanadium compromises PVD utilization.
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Affiliation(s)
- Christine Baysse
- Laboratory of Microbial Interactions, Department of Immunology, Parasitology and Ultrastructure, Flanders Interuniversity Institute of Biotechnology and Vrije Universiteit Brussel, Paardenstraat 65, B-1640 Sint Genesius Rode, Belgium1
| | - Daniel De Vos
- Laboratory of Microbial Interactions, Department of Immunology, Parasitology and Ultrastructure, Flanders Interuniversity Institute of Biotechnology and Vrije Universiteit Brussel, Paardenstraat 65, B-1640 Sint Genesius Rode, Belgium1
| | - Yann Naudet
- Laboratory of Microbial Interactions, Department of Immunology, Parasitology and Ultrastructure, Flanders Interuniversity Institute of Biotechnology and Vrije Universiteit Brussel, Paardenstraat 65, B-1640 Sint Genesius Rode, Belgium1
| | - Alain Vandermonde
- Laboratory of Microbial Interactions, Department of Immunology, Parasitology and Ultrastructure, Flanders Interuniversity Institute of Biotechnology and Vrije Universiteit Brussel, Paardenstraat 65, B-1640 Sint Genesius Rode, Belgium1
| | - Urs Ochsner
- University of Colorado Health Sciences Center, Microbiology, Box B-175, 4200 E Ninth Avenue, Denver, CO 80202, USA2
| | - Jean-Marie Meyer
- Laboratoire de Microbiologie et de Génétique, Université Louis Pasteur, UPRES-A 7010, F-67000 Strasbourg, France3
| | - Herbert Budzikiewicz
- Institut für Organische Chemie der Universität zu Köln, Greinstrasse 4,D-50939 Köln, Germany4
| | - Matthias Schäfer
- Institut für Organische Chemie der Universität zu Köln, Greinstrasse 4,D-50939 Köln, Germany4
| | - Regine Fuchs
- Institut für Organische Chemie der Universität zu Köln, Greinstrasse 4,D-50939 Köln, Germany4
| | - Pierre Cornelis
- Laboratory of Microbial Interactions, Department of Immunology, Parasitology and Ultrastructure, Flanders Interuniversity Institute of Biotechnology and Vrije Universiteit Brussel, Paardenstraat 65, B-1640 Sint Genesius Rode, Belgium1
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Stern A, Davison AJ, Wu Q, Moon J. Effects of ligands on reduction of oxygen by vanadium(IV) and vanadium(III). Arch Biochem Biophys 1992; 299:125-8. [PMID: 1444445 DOI: 10.1016/0003-9861(92)90253-s] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
V(IV) and V(III) reduce molecular oxygen with increasing rates as the pH is raised from 6.0 to 7.4. Under all conditions tested, V(IV) is the more efficient reductant. EDTA and ATP generally inhibit the reduction of oxygen by V(III) and V(IV). In contrast, desferrioxamine accelerates the reduction of oxygen by V(IV) but with decreasing effectiveness at pH 7.4 compared to pH 6.0, while desferrioxamine accelerates the reduction of oxygen by V(III) only at pH 6.0. Histidine enhances the reduction of oxygen by V(IV) at pH 7.0 and 7.4. The observed rates of oxygen reduction by V(III) and V(IV) imply that the intracellular distribution of vanadium among its redox states reflects not an equilibrium but a steady state.
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Affiliation(s)
- A Stern
- Bioenergetics Research Laboratory, Faculty of Applied Sciences, School of Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
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