Characteristics of glucoamylase from Aspergillus terreus

Glucose was the only product of starch hydrolysis liberated by glucoamylase. The enzyme was a glycoprotein with an isoelectric point at pH 3·4 and was optimally active at pH 4·0 and 60°C. It was remarkably stable over a wide range of pH and at elevated temperatures. Divalent Mg²⁺'and Ca²⁺ slightly stimulated glucoamylase activity. The enzyme exhibited specificity for substrates containing α(1 → 4) glucosidic linkages and the Km for starch hydrolysis was 4·0 g/l.