Glucanohydrolase, amylopectin

The latest International Union Biochemicals report includes an enzyme 3.2.1.41 a-dextrin endo-l,6-a-glucosidase, other names limit dextrinase, amylopectin 6-glucanohydrolase, pullulanase. 

Isoamylase [9067-73-6] (glycogen-6-glucanohydrolase) and pullulanase [9012-47-9] (pullulan-6-glucanohydrolase) hydrolyzes a-l,6-glucosidic bonds of starch. When amylopectin is treated with a pullulanase, linear amylose fragments are obtained. Using a heat- and acid-stable pullulanase in combination with saccharifying enzymes makes the starch conversion reactions more efficient (71). 

At the request of the Codex Committee on Food Additives and Contaminants at its thirty-eighth session (Codex Alimentarius Commission, 2006), the Committee evaluated the enzyme isoamylase (glycogen a-1,6-glucanohydrolase EC 3.2.1.68). Isoamylase catalyses the hydrolysis of 1,6-a-D-glucosidic branch linkages in glycogen, amylopectin and their beta-limit dextrine. It has no or only limited activity on linear polysaccharides linked by a-1,6-glycosidic bonds (e.g. pullulan) and on alpha-limit dextrine. 

Starch is a utiHsable polysaccharide easily digested in the small intestine. In the digestion of starch, the enzymes a-amylase (in saliva), pancreatic a-amylase and isoamylase (isomaltase or glycogen 6-glucanohydrolase) cleave the a-(1 6) of amylopectin and glycogen. 

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