[Defects in antioxidant defence enhance glyoxal toxicity in the yeast Saccharomyces cerevisiae]

Glyoxal being either exogenous or endogenous compound belongs to reactive carbonyl species. In particular, its level increases under disturbance of the balance of glucose intracellular metabolism as well as of other reductive carbohydrates. Having two carbonyl reactive groups, glyoxal readily enters glycation reaction that results in carbonyl stress development. Investigations of different model systems demonstrate a strong relationship between carbonyl and oxidative stress. However, a possible role of antioxidant system in the organisms' defence against carbonyl stress is poor understood. In addition, the influence of glyoxal on living organisms is less studied than the effect of such carbonyl reactive species as malonic aldehyde or methylglyoxal. To study a potential role of antioxidant system in organisms' defence against carbonyl stress induced by glyoxal, the baker's yeast Saccharomyces cerevisiae was used. It has been found that strains with different defects in the antioxidant defence were more sensitive to glyoxal as compared with parental wild strain. Therefore, the data obtained in the present study confirm the relationship between carbonyl and oxidative stress and reveal the important role of antioxidant system in baker's yeast defence against carbonyl stress induced by glyoxal.