Purification of Peptidases of Aspergillus oryzae and Some Properties of the Purified Peptidases

The purification of Aspergillus oryzae peptidases was attempted by the fractional precipitation with acetone, ammonium sulphate, and by starch zone electrophoresis. We, thus, achieved a great success in the separation of dipeptidase free from aminopolypeptidase and proteinase as well as in the separation of aminopolypeptidase free from dipeptidase and proteinase.

The specific activity (C₀) of the former (leucylglycine hydrolysis) was 7000 and that of the latter (leucylglycylglycine hydrolysis) 22000.

The leucylglycine dipeptidase was remarkably activated by Zn⁺⁺, and Co⁺⁺. Some other enzyme properties were also found and are discussed.