[Changes in proteinase A and B activity during glucose repression in the yeast Saccharomyces cerevisiae]

The divisible and indivisible yeast S. cerevisiae were subjected to glucose repression by increasing the glucose content in the growth medium up to 10%. Under these conditions the total activities of both proteinases did not change significantly, while those of free (i.e. not bound to natural inhibitors) proteinases were increased manyfold. This effect is probably due to liberation of the proteinases from the vacuoles and digestion of cytosolic proteinase inhibitors.