PREPARATION AND STABILITY OF EXO-AMYLOLYTIC ENZYMES CHEMICALLY COUPLED TO MICROCRYSTALLINE CELLULOSE

The preparation of active, water-insoluble derivatives of β- and γ-amylase by chemical coupling with a diazotised 3-(p-aminophenoxy)-2-hydroxypropyl ether of cellulose, and a water-insoluble derivative of β-amylase by coupling with a 2-hydroxy-3-(p-isothiocyanatophenoxy)propyl ether of cellulose is described. The activity retained on insolubilisation is considerably higher than that commonly retained on water-insolubilisation of hydrolytic enzymes active against macromolecular substrates. It is suggested that this is connected with the exo-hydrolytic character of β- and γ-amylase. The insoluble enzymes are relatively more resistant to heat denaturation than the free enzymes in solution. © 1969.