Vanadium metabolism in wild type and respiratory‐deficient strains of S. cerevisiae

Vanadium metabolism was studied in a wild type and respiratory‐deficient strains of S. cerevisiae. Inhibition of growth by vanadate [V(+5)], vanadate accumulation, and conversion of medium vanadate [V(+5)] to both cell‐associated and medium vanadyl [V(+4)] and vanadate [V(+5)] were compared. The growth of both the parental and respiratory‐deficient strains was inhibited by vanadate at concentrations greater than or equal to 1 mM. Both parental and respiratory‐deficient strains accumulated vanadate and converted medium vanadate to cellular vanadyl as detected using electron spin resonance (ESR). The accumulation of cell‐associated vanadyl was correlated with the loss of medium vanadate in both strains using a chemical assay. In contrast, the respiratory‐deficient strain showed a greater amount of a cell‐associated vanadate compound, as detected with vanadium‐51 nuclear magnetic resonance (⁵¹V‐NMR), than the wild strain or a representative respiratory‐competent vanadate‐resistant mutant. These data imply that mitochondrial function may be directly involved in vanadium metabolism.