Glucosidases
Encyclopedia
Glucosidases are glycoside hydrolase
Glycoside hydrolase
Glycoside hydrolases catalyze the hydrolysis of the glycosidic linkage to release smaller sugars...

 enzymes categorized under the EC number
EC number
The Enzyme Commission number is a numerical classification scheme for enzymes, based on the chemical reactions they catalyze....

 3.2.1.

Function

α-glucosidases are enzymes involved in breaking down complex carbohydrates such as starch
Starch
Starch or amylum is a carbohydrate consisting of a large number of glucose units joined together by glycosidic bonds. This polysaccharide is produced by all green plants as an energy store...

 and glycogen
Glycogen
Glycogen is a molecule that serves as the secondary long-term energy storage in animal and fungal cells, with the primary energy stores being held in adipose tissue...



They catalyze the cleavage of individual glucosyl residues from various glycoconjugates
Glycoconjugates
Glycoconjugates is the general classification for carbohydrates covalently linked with other chemical species.Glycoconjugates are very important compounds in biology and consist of many different categories such as glycoproteins, glycopeptides, peptidoglycans, glycolipids, and lipopolysaccharides...

 including alpha- or beta-linked polymers of glucose.

Members

Different sources include different members in this class. Members marked with a "#" are considered by MeSH
Medical Subject Headings
Medical Subject Headings is a comprehensive controlled vocabulary for the purpose of indexing journal articles and books in the life sciences; it can also serve as a thesaurus that facilitates searching...

 to be glucosidases.
Name EC Description
>-
| α-Amylase 
digestive
Digestion
Digestion is the mechanical and chemical breakdown of food into smaller components that are more easily absorbed into a blood stream, for instance. Digestion is a form of catabolism: a breakdown of large food molecules to smaller ones....

 enzyme in mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

s
>-
| β-Amylase 
plant
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...

 enzyme to break down starch
Starch
Starch or amylum is a carbohydrate consisting of a large number of glucose units joined together by glycosidic bonds. This polysaccharide is produced by all green plants as an energy store...


>-
| γ-Amylase 
>-
| Cellulase
Cellulase
400px|thumb|right|alt = Colored dice with checkered background|Ribbon representation of the Streptomyces lividans beta-1,4-endoglucanase catalytic domain - an example from the family 12 glycoside hydrolases...

 #
cellulose
Cellulose
Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to over ten thousand β linked D-glucose units....

 from plant material
>-
| Sucrase-isomaltase
Sucrase-isomaltase
Sucrase-isomaltase is a glucosidase enzyme.A deficiency is responsible for sucrose intolerance.-External links:*...

 
>-
| Acid α-glucosidase #
Glycogen storage disease type II
Glycogen storage disease type II
Glycogen storage disease type II is an autosomal recessive metabolic disorder which damages muscle and nerve cells throughout the body. It is caused by an accumulation of glycogen in the lysosome due to deficiency of the lysosomal acid alpha-glucosidase enzyme...


>-
| Beta-glucosidase #
gaucher's disease
Gaucher's disease
Gaucher's disease is a genetic disease in which a fatty substance accumulates in cells and certain organs.Gaucher's disease is the most common of the lysosomal storage diseases. It is caused by a hereditary deficiency of the enzyme glucosylceramidase. The enzyme acts on the fatty acid...



>-
| Lactase
Lactase
Lactase , a part of the β-galactosidase family of enzymes, is a glycoside hydrolase involved in the hydrolysis of the disaccharide lactose into constituent galactose and glucose monomers...

 
β-galactosidase
Beta-galactosidase
β-galactosidase, also called beta-gal or β-gal, is a hydrolase enzyme that catalyzes the hydrolysis of β-galactosides into monosaccharides. Substrates of different β-galactosidases include ganglioside GM1, lactosylceramides, lactose, and various glycoproteins...

 family, breaks down milk
Milk
Milk is a white liquid produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals before they are able to digest other types of food. Early-lactation milk contains colostrum, which carries the mother's antibodies to the baby and can reduce the risk of many...

 sugars, and its absence in adult
Adult
An adult is a human being or living organism that is of relatively mature age, typically associated with sexual maturity and the attainment of reproductive age....

hood causes lactose intolerance
Lactose intolerance
Lactose intolerance, also called lactase deficiency or hypolactasia, is the inability to digest and metabolize lactose, a sugar found in milk...


>-
| Debranching enzyme #
>-
| Pullulanase
Pullulanase
Pullulanase is a specific kind of glucanase, an amylolytic exoenzyme, that degrades pullulan. 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...

 
has been used as a detergent
Detergent
A detergent is a surfactant or a mixture of surfactants with "cleaning properties in dilute solutions." In common usage, "detergent" refers to alkylbenzenesulfonates, a family of compounds that are similar to soap but are less affected by hard water...


Clinical significance

They are targeted by alpha-glucosidase inhibitor
Alpha-glucosidase inhibitor
Alpha-glucosidase inhibitors are oral anti-diabetic drugs used for diabetes mellitus type 2 that work by preventing the digestion of carbohydrates . Carbohydrates are normally converted into simple sugars , which can be absorbed through the intestine...

s such as acarbose
Acarbose
Acarbose is an anti-diabetic drug used to treat type 2 diabetes mellitus and, in some countries, prediabetes. It is a generic sold in Europe and China as Glucobay , in North America as Precose , and in Canada as Prandase...

 and miglitol to control diabetes mellitus type 2
Diabetes mellitus type 2
Diabetes mellitus type 2formerly non-insulin-dependent diabetes mellitus or adult-onset diabetesis a metabolic disorder that is characterized by high blood glucose in the context of insulin resistance and relative insulin deficiency. Diabetes is often initially managed by increasing exercise and...

.
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