Redox and specific effects of vanadium ions on respiratory enzymes

The effects of vanadium ions on the activities of enzymes of aerobic and anaerobic respiratory chains were investigated in vitro and in situ employing 1H-, 14N-, 31P- and 51V- nuclear magnetic resonance spectroscopy, electron paramagnetic resonance spectroscopy and spectrophotometry. Vanadate and vanadyl ions produced either non-specific redox or specific activation or inhibition of respiratory enzymes. The oxidants molybdate and chromate and the reductant dithiothreitol were used to distinguish between non-specific and specific effects of vanadium ions on enzyme activities. The results suggested that components of anaerobic respiratory chains were more susceptible to vanadium ions than those of the aerobic respiratory chain.