[Immobilization of aspergillus oryzae aminopeptidase on organic and inorganic carriers]

The process of Asp. oryzae aminopeptidase immobilization on organic (AE-cellulose, sepharose 4B, Sephadex G-200) and inorganic (SCh-2, SCh-3 sylochromes and KCK N 1 silicagel) carriers was studied. Aminopeptidase immobilized on Sephadex G-200 contains the largest amount of protein (80 mg per 1 g of carrier) and is the most active of all other preparations. The immobilized preparations retain the temperature optimum, like the soluble form, at 60 degrees C, except the preparation immobilized on AE-cellulose (50 degrees C). At temperatures of 70, 80 degrees C the obtained preparations are more thermostable than the initial enzyme. The pH-stability zone for the preparations immobilized by means of sylochrome-3 and Sephadex G-200 is wider to some extent as compared to the soluble enzyme. When studying the substrate specificity it is established that leucyl-glycyl-glycine is the best substrate for both the soluble form and the immobilized preparations. Multiple application of the immobilized aminopeptidase is shown to be possible.