Usuari:ABassols/proves
Pululanasa
[modifica]La Pululanasa (EC 3.2.1.41, limit dextrinase, amylopectin 6-glucanohydrolase, bacterial debranching enzyme, debranching enzyme, alpha-dextrin endo-1,6-alpha-glucosidase, R-enzyme, pullulan alpha-1,6-glucanohydrolase) es un tipus específic de "glucanasa", un "exoenzim" amilolitic que degrada el pululà. Està produida per bacteris gram-negatius del genere Klebsiella. Es una lipoproteina extracel·lular, ancorada a la membrana plasmàtica. Les pululanases de tipus I ataquen especíificament enllaços α-1,6, mentre que les pululanases de tipus II també hidrolitzen enllaços α-1,4.
is a specific kind of glucanase, an amylolytic exoenzyme, that degrades pullulan.[1][2][3] 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 alpha-1,6-glycosidic bonds. Pullulanase will hydrolytically cleave pullulan (alpha-glucan polysaccharides).
References
[modifica]- ↑ «Glycogen and starch debranching enzymes». A: The Enzymes. 5. 3rd. New York: Academic Press, 1972, p. 191–234.
- ↑ «Pullulanase (an amylopectin and glycogen debranching enzyme) from Aerobacter aerogenes». Methods Enzymol., vol. 8, 1966, pàg. 555–559. DOI: 10.1016/0076-6879(66)08100-X.
- ↑ «Observations on the specificity and nomenclature of starch debranching enzymes». J. Appl. Glycosci., vol. 44, 1997, pàg. 83–85.
External links
[modifica]- «ABassols/proves» (en anglès). Medical Subject Headings.