Abstract
Vacuolar sap was separated by intracellular perfusion and the distribution of proteases was studied in the giant alga Chara australis. Caseinolytic and hemoglobin-digesting activities were found to be higher at low pH, and about 85 % of total activity was localized in the central vacuole. The optimal pH for carboxypeptidase activity measured using N-carbo-benzoxy-L-phenylalanyl-L-alanineas a substrate was around 5, and about 95 % of total activity was localized in the vacuole. Moreover a substantial portion (40 %) of aminopeptidase activity, measured at pH 5.5 using L-leucine-β-naphthylamide as a substrate, was found in the vacuole.
