Maltokinase | |||||||||
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Identifiers | |||||||||
EC no. | 2.7.1.175 | ||||||||
Databases | |||||||||
IntEnz | IntEnz view | ||||||||
BRENDA | BRENDA entry | ||||||||
ExPASy | NiceZyme view | ||||||||
KEGG | KEGG entry | ||||||||
MetaCyc | metabolic pathway | ||||||||
PRIAM | profile | ||||||||
PDB structures | RCSB PDB PDBe PDBsum | ||||||||
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Maltokinase (EC 2.7.1.175) is an enzyme with systematic name ATP:alpha-maltose 1-phosphotransferase. [1] This enzyme catalyses the following chemical reaction
This enzyme requires Mg2+ for activity.
A disaccharide is the sugar formed when two monosaccharides are joined by glycosidic linkage. Like monosaccharides, disaccharides are simple sugars soluble in water. Three common examples are sucrose, lactose, and maltose.
An amylase is an enzyme that catalyses the hydrolysis of starch into sugars. Amylase is present in the saliva of humans and some other mammals, where it begins the chemical process of digestion. Foods that contain large amounts of starch but little sugar, such as rice and potatoes, may acquire a slightly sweet taste as they are chewed because amylase degrades some of their starch into sugar. The pancreas and salivary gland make amylase to hydrolyse dietary starch into disaccharides and trisaccharides which are converted by other enzymes to glucose to supply the body with energy. Plants and some bacteria also produce amylase. Specific amylase proteins are designated by different Greek letters. All amylases are glycoside hydrolases and act on α-1,4-glycosidic bonds.
Maltose, also known as maltobiose or malt sugar, is a disaccharide formed from two units of glucose joined with an α(1→4) bond. In the isomer isomaltose, the two glucose molecules are joined with an α(1→6) bond. Maltose is the two-unit member of the amylose homologous series, the key structural motif of starch. When beta-amylase breaks down starch, it removes two glucose units at a time, producing maltose. An example of this reaction is found in germinating seeds, which is why it was named after malt. Unlike sucrose, it is a reducing sugar.
Maltase is one type of alpha-glucosidase enzymes located in the brush border of the small intestine. This enzyme catalyzes the hydrolysis of disaccharide maltose into two simple sugars of glucose. Maltase is found in plants, bacteria, yeast, humans, and other vertebrates. It is thought to be synthesized by cells of the mucous membrane lining the intestinal wall.
Acarbose (INN) is an anti-diabetic drug used to treat diabetes mellitus type 2 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.
Brown rice (malt) syrup, also known as rice syrup or rice malt, is a sweetener which is rich in compounds categorized as sugars and is derived by steeping cooked rice starch with saccharifying enzymes to break down the starches, followed by straining off the liquid and reducing it by evaporative heating until the desired consistency is reached. The enzymes used in the saccharification step are supplied by an addition of sprouted barley grains to the rice starch or by adding bacterial- or fungal-derived purified enzyme isolates.
Glucose syrup, also known as confectioner's glucose, is a syrup made from the hydrolysis of starch. Glucose is a sugar. Maize (corn) is commonly used as the source of the starch in the US, in which case the syrup is called "corn syrup", but glucose syrup is also made from potatoes and wheat, and less often from barley, rice and cassava.p. 21
Isomaltase is an enzyme that breaks the bonds linking saccharides, which cannot be broken by amylase or maltase. It digests polysaccharides at the alpha 1-6 linkages. Its substrate, alpha-limit dextrin, is a product of amylopectin digestion that retains its 1-6 linkage. The product of the enzymatic digestion of alpha-limit dextrin by isomaltase is maltose.
β-Amylase is an enzyme with the systematic name 4-α-D-glucan maltohydrolase. It catalyses the following reaction:
Maltotriose is a trisaccharide consisting of three glucose molecules linked with α-1,4 glycosidic bonds.
In enzymology, a maltose α-D-glucosyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a maltose epimerase is an enzyme that catalyzes the chemical reaction
In enzymology, a maltose-transporting ATPase (EC 3.6.3.19) is an enzyme that catalyzes the chemical reaction
In enzymology, a maltose O-acetyltransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a maltose synthase (EC 2.4.1.139) is an enzyme that catalyzes the chemical reaction
In enzymology, a pyruvate, water dikinase (EC 2.7.9.2) is an enzyme that catalyzes the chemical reaction
In enzymology, a tropomyosin kinase is an enzyme that catalyzes the chemical reaction
Maltase-glucoamylase, intestinal is an enzyme that in humans is encoded by the MGAM gene.
Starch synthase (maltosyl-transferring) is an enzyme with systematic name alpha-maltose 1-phosphate:(1->4)-alpha-D-glucan 4-alpha-D-maltosyltransferase. This enzyme catalyses the following chemical reaction
L-cysteine:1D-myo-inositol 2-amino-2-deoxy-alpha-D-glucopyranoside ligase is an enzyme with systematic name L-cysteine:1-O-(2-amino-2-deoxy-alpha-D-glucopyranosyl)-1D-myo-inositol ligase (AMP-forming). This enzyme catalyses the following chemical reaction