Effect of zinc ion on generation and scavenging reaction of reactive oxygen species

Abstract

Zinc is an essential metal but toxic to baker’s yeast at high concentration. In this report, the effect of zinc on the enzymes that generate or scavenge reactive oxygen species was analyzed. Zinc ion potently inhibited glucose 6-phosphate dehydrogenase, NADP dependent isocitrate dehydrogenase and glutathione reductase, whereas slightly activated NADPH: quinone oxidoreductase, which generates superoxide anion and hydrogen peroxide. Toxicity of zinc on yeast can be principally explained by the reactive oxygen species increased due to the inhibition of glutathione reductase.