Catalases protect cellular proteins from oxidative modification in Saccharomyces cerevisiae

The yeast Saccharomyces cerevisiae cells had higher antioxidant enzyme activities under growth in ethanol than that in glucose as a carbon and energy source. The correlations between catalase activity and protein carbonyl level (r(2) = 0.857), between catalase and glucose-6-phosphate dehydrogenase activities (r(2) = 0.924) and between protein carbonyl levels and glucose-6-phosphate dehydrogenase activity (r(2) = 0.988) under growth in ethanol were found. Growing in ethanol the strain deficient in cytosolic and peroxisomal catalases had 7.1-fold higher level of carbonyl proteins than that of wild-type strain. Our data suggest that in vivo catalases may protect glucose-6-phosphate dehydrogenase against oxidative inactivation. (C) 2004 International Federation for Cell Biology. Published by Elsevier Ltd. All rights reserved.