Macromolecule recognition of Bacillus stearothermophilus neopullulanase

Neopullulanase was a key enzyme in opening the door to clarification of the concept of the alpha-amylase family. The enzyme catalyzes both hydrolysis and transglycosylation of alpha-1,4- and alpha-1,6-glucosidic linkages at one active center. Different activities of neopullulanase toward amylose and amylopectin was noted previously. We recently found a unique way, using macromolecules, for recognition of the enzyme. A mixture of amylose and amylopectin from various sources was used as the substrate. Neopullulanase completely hydrolyzed amylose, but scarcely affected amylopectin. Although the molecular mass of amylopectin (approximately 10(8)Da) decreased slightly, the degradation of amylopectin completely halted at the molecular weight of approximately 10(7) Da. This difference in action on two macromolecules was also found in cyclomaltodextrinase and maltogenic amylase from Bacillus licheniformis.