Degradation of abnormal proteins in growing yeast

Degradation of abnormal proteins in Saccharomyces cerevisiae, synthesized in an ethanol medium in the presence of 0.1 mM canavanine, proceeded more rapidly than that of the normal ones, the degradation constant of the 'long-lived' fraction being most affected. Higher concentrations of the analogue had an adverse effect on protein degradation during subsequent growth. Degradation of normal and abnormal proteins was suppressed by glucose but was increased substantially in cell-free extracts. This suggests that their internalization into the digestive organelle may be an important step in protein catabolism in yeast.