pullulanase

{{Short description|Enzyme}}

{{Infobox enzyme

| Name = Pullulanase

| EC_number = 3.2.1.41

| CAS_number = 9075-68-7

| GO_code =

| image = 2yoc.jpg

| width = 270

| caption = Debranching enzyme homotetramer, Klebsiella oxytoca

}}

Pullulanase ({{EnzExplorer|3.2.1.41}}, limit dextrinase, amylopectin 6-glucanohydrolase, bacterial debranching enzyme, debranching enzyme, α-dextrin endo-1,6-α-glucosidase, R-enzyme, pullulan α-1,6-glucanohydrolase) is a specific kind of glucanase, an amylolytic exoenzyme, that degrades pullulan.{{cite book | chapter = Glycogen and starch debranching enzymes | title = The Enzymes |author1-link=Ernest Y. C. Lee | vauthors = Lee EY, Whelan WJ |year = 1972 |volume = 5 |pages = 191–234 | veditors = Boyer PD |edition = 3rd |publisher = Academic Press |location = New York }}{{cite book | title = Complex Carbohydrates | vauthors = Bender H, Wallenfels K | chapter = Pullulanase (An amylopectin and glycogen debranching enzyme) from Aerobacter aerogenes |year = 1966 |volume = 8 |pages = 555–559 | doi = 10.1016/0076-6879(66)08100-X | series = Methods in Enzymology | isbn = 9780121818081 }}{{cite journal | title = Observations on the specificity and nomenclature of starch debranching enzymes | vauthors = Manners DJ |journal = J. Appl. Glycosci. |year = 1997 |volume = 44 |pages = 83–85 }} It is produced as an extracellular, cell surface-anchored lipoprotein by Gram-negative bacteria of the genus Klebsiella. Type I pullulanases specifically attack α-1,6 linkages, while type II pullulanases are also able to hydrolyse α-1,4 linkages. It is also produced by some other bacteria and archaea. Pullulanase is used as a processing aid in grain processing biotechnology (production of ethanol and sweeteners).

Pullulanase is also known as pullulan-6-glucanohydrolase (Debranching enzyme). Its substrate, pullulan, is regarded as a chain of maltotriose units linked by α-1,6-glycosidic bonds. Pullulanase will hydrolytically cleave pullulan (α-glucan polysaccharides).