Wb. Dasilva et Rm. Peralta, PURIFICATION AND CHARACTERIZATION OF A THERMOSTABLE GLUCOAMYLASE FROMASPERGILLUS-FUMIGATUS, Canadian journal of microbiology, 44(5), 1998, pp. 493-497
A thermostable glucoamylase from Aspergillus fumigatus was purified to
homogeneiry. It was a glycoprotein with 23% carbohydrate content and
an apparent molecular mass of 42 kDa. The enzyme showed maximal activi
ties at pH 4.5-5.5 and 65 degrees C and preferentially attacked polysa
charides, such as starch, glycogen, amylopectin, and amylose, rather t
han maltose and maltoriose. The K-m and V-max of soluble starch hydrol
ysis at 40 degrees C and pH 5.0 were 0.1 mg.mL(-1) and 161 mu mol gluc
ose equivalents liberated.min(-1).mg protein(-1), respectively. The pu
rified enzyme was remarkably insensitive to glucose. It was not affect
ed by 500 mM D-glucose and retained about 80% of its original activity
in the presence of 1000 mM of this sugar.