Enzyme Activity Measurement for Isopullulanase

Creative Enzymes offers reliable activity measurement for isopullulanase. The quality of our results is assured with the most advanced instrument and leading technology. We outpace our competitors with a quick turnover of activity assays in response to the request of either a typical activity determination or a customized task.

Isopullulanase (EC 3.2.1.57; pullulan 4-glucanohydrolase) is an enzyme that cleaves only the internal α-1,4-glucosidic bonds of pullulan on the reducing side with respect to the α-1,6 branch point and releases isopanose. Isopullulanase also hydrolyzes substrates containing the panose (Glc-α-(1→6)-Glc-α-(1→4)-Glc) structure and cleaves the α-1,4-glucosidic linkage in the panose motif. Because isopullulanase can precisely recognize the structural differences between α-1,4- and α-1,6-glycosidic linkages, it is exploited in structural analysis of oligo- and polysaccharides. Nonetheless, isopullulanase has no action on starch practically.

The enzymes hydrolyzing pullulan have been classified mainly into three types based on the substrate specificity and the product. (i) Pullulanase (EC 3.2.1.41), which hydrolyzes α-1,6-glucosidic linkages to form maltotriose; (ii) Alpha-amylase (EC 3.2.1.1) from Thermoactinomyces vulgaris R-47 and neopullulanase (EC 3.2.1.135), which hydrolyze α-1,4-glucosidic linkages to yield panose; (iii) Isopullulanase which hydrolyzes the other α-1,4-glucosidic linkages to yield isopanose. Among these enzymes, isopullulanase is the sole enzyme classified into the GH 49 family. Interestingly, isopullulanase does not hydrolyze dextran at all, while all other GH 49 family enzymes are dextran-hydrolyzing enzymes. Note that, the primary structure of isopullulanase is completely different from that of isomaltodextranase or other pullulan hydrolases, but surprisingly, is highly similar to that of several dextranases that do not hydrolyze pullulan.

Hence, detailed studies on the action mechanisms of isopullulanase will reveal the molecular basis of its catalytic activity, which will further inspire engineering and modifications of the enzyme to achieve various substrate specificity and higher efficiency as desired by food and chemical industries. Hence, Creative Enzymes developed the most reliable enzyme activity measurement for isopullulanase to facilitate such research. The activity of isopullulanase is determined by using the spectrophotometric assay. Our test results are the most trusted and accurate, indicated by regularly repeated inquiries from many customers. Overall, Creative Enzymes is your trusty-worthy partner and will always support your research in a professional fashion.

Figure: The crystal structure of isopullulanase from Aspergillus niger ATCC 9642.
PDB: 1WMR