EC 5.3.1.9 From Bacillus subtilis. Electrophoretically homogeneous (MW 51,500). Several bands on isoelectric focusing (pI 4.8-5.0). In 3.2 M ammonium sulphate. Specific activity: 250 U/mg of protein (25°C, pH 7.6) or 483 U/mg of protein (40°C, pH 7.6). Contaminants: hexokinase < 0.002 %; glucose 6-phosphate dehydrogenase < 0.0001 %; phosphomannose isomerase 0.016 %; α-glucosidase < 0.00001 %; and ?-glucosidase; < 0.0005 %. Stable at 4°C for > 4 years.