Affiliation: | (1) Departamento de Bioquímica, Instituto de Investigaciones Biomédicas Alberto Sols UAM/CSIC, Facultad de Medicina, Arzobispo Morcillo 4, 28029 Madrid, Spain;(2) Instituto de Biología Molecular e Celular, Universidade do Porto, Instituto de Ciências Biomédicas Abel Salazar, Portugal |
Abstract: | As has been previously shown, Saccharomyces cerevisiae grown in 2% or 0.025% glucose uses this carbohydrate by the fermentative or oxidative pathways, respectively. Depending on the glucose concentration in the medium, the effect of the addition of H2O2 on the level of ATP and on glyceraldehyde-3-phosphate dehydrogenase (GAPDH) activity differed. In the presence of 2% glucose, ATP and GAPDH decreased sharply during the first few minutes of treatment, whereas in the presence of 0.025% glucose, GAPDH activity decreased similarly, but the ATP level remained practically unchanged. The addition of 3 mM glutathione to the culture media prevented the depletion of ATP levels and GAPDH activity in the presence of H2O2. Catalase and superoxide dismutase activities did not vary significantly when yeast cells were grown either in 2% or in 0.025% glucose. |