PRODUCTS

AMYLODEXTRIN

AMYLODEXTRIN = amylo-1,6-glucosidase

CAS No. : 9012-47-9
EC no. : 3.2.1.33

Description: This enzyme hydrolyses an unsubstituted glucose unit linked by an α(1→6) bond to an α(1→4) glucose chain.
Amylodextrin enzyme activity found in mammals and yeast is in a polypeptide chain containing two active centres.
Amylodextrin other activity is similar to that of EC 2.4.1.25 (4-α-glucanotransferase), which acts on the glycogen phosphorylase limit dextrin chains to expose the single glucose residues, which the 6-α-glucosidase activity can then hydrolyse.
Together, these two activities constitute the glycogen debranching system.

Form: Liquid or lyophilized powder

Enzyme Commission Number: EC 3.2.1.33

CAS No. : 9012-47-9

Storage: Store it at +4 ºC for short term.
For long term storage, store it at -20 ºC～-80 ºC.

Synonyms: amylo-1,6-glucosidase; dextrin 6-α-D-glucosidase; amylopectin 1,6-glucosidase; dextrin-1,6-glucosidase; glycogen phosphorylase-limit dextrin α-1,6-glucohydrolase

Reaction: Hydrolysis of (1→6)-α-D-glucosidic branch linkages in glycogen phosphorylase limit dextrin

Notes: This item requires custom production and lead time is between 5-9 weeks.
We can custom produce according to your specifications.

End product of hydrolysis of amylopectin by β-amylase; further hydrolysis requires amylo-1,6-glucosidase, which attacks the branch points.
Identified by its color reaction with iodine (amylodextrin turns blue).
Compare: achroodextrin, erythrodextrin.

As nouns the difference between dextrin and amylose is that dextrin is (carbohydrate) any of a range of polymers of glucose, intermediate in complexity between maltose and starch, produced by the enzymatic hydrolysis of starch; used commercially as adhesives while amylose is (carbohydrate) the soluble form of starch (the insoluble form being amylopectin) that is a linear polymer of glucose.

PRODUCT DESCRIPTION
Amylodextrin product is produced by submerged fermentation of Bacillus subtilis followed by purification and formulation.
Amylodextrin is a thermal stable debranching enzyme able to work at low pH, and is widely used in brewing, starch sugar processing, monosodium glutamate and alcohol fermentation, etc.

MECHANISM
Pullulanase is a type of isoamylase which can selectively hydrolyze α-1,6-glucosidic linkage in pullulan, starch and oligosaccharides, thereby, making the complete hydrolysis of branched starch possible.
Together with other enzymes (glucoamylase, β-Amylase) it speeds up saccharification and increase glucose or maltose yield.

APPLICATION RECOMMENDATION
Glucose production: The recommended dosage is 0.35-0.6L per ton of dry starch together with glucoamylase together in saccharification step.
Maltose syrup: The recommended dosage is 1-2L per ton of dry starch together with Fungal Alpha-Amylase can together use in saccharification step.
In brewhouse: The recommended dosage is 0.4-0.8L of the enzyme preparation per ton of total raw materials.
Amylodextrin used for degradation of amylopectin and production of dry beer.

The dosage has to be optimized based on each application, the raw material specifications, product expectation and processing parameters.
Amylodextrin is better to begin the test with the convenient volume.

SAFE HANDLING PRECAUTIONS
Enzyme preparations are proteins that may induce sensitization and cause allergic type of symptoms in susceptible individuals.
Prolonged contact may cause minor irritation for skin, eyes or nasal mucosa.
Any direct contact with human body should be avoided.
If irritation or allergic response for skin or eyes develops, please consult a doctor.

WARNINGS
Keep sealed after use every time to avoid microbial infections and inactivation of enzymes until its finish.

PACKAGE AND STORAGE
Package 25kgs/drum; 1,125kgs/drum.

Storage： Keep sealed in a dry and cool place and avoid direct sunlight.
Slight sedimentation is acceptable since it will not impact performance of the product.
Shelf life: 12 months in a dry and cool place.

Amylo-alpha-1,6-glucosidase (EC 3.2.1.33, amylo-1,6-glucosidase, dextrin 6-alpha-D-glucosidase, amylopectin 1,6-glucosidase, dextrin-1,6-glucosidase, glycogen phosphorylase-limit dextrin alpha-1,6-glucohydrolase) is an enzyme with systematic name glycogen phosphorylase-limit dextrin 6-alpha-glucohydrolase.
Amylodextrin enzyme catalyses the following chemical reaction

Hydrolysis of (1->6)-alpha-D-glucosidic branch linkages in glycogen
Amylodextrin enzyme hydrolyses an unsubstituted (1->4)-linked glucose chain.

Amylodextrin enzyme hydrolyses an unsubstituted glucose unit linked by an alpha(1->6) bond to an alpha(1->4) glucose chain.
Amylodextrin enzyme activity found in mammals and yeast is in a polypeptide chain containing two active centres.
Amylodextrin other activity is similar to that of EC 2.4.1.25 (4-alpha-glucanotransferase), which acts on the glycogen phosphorylase limit dextrin chains to expose the single glucose residues, which the 6-alpha-glucosidase activity can then hydrolyse.
Together, these two activities constitute the glycogen debranching system.

Synonyms
amylo-1,6-glucosidase,
debrancher enzyme,
amylo-alpha-1,
6-glucosidase,
debrancher protein,
amylo-alpha-1,
6-glucosidase activity,
amylo-1,
6-glucosidase/4-alpha-glucanotransferase,
dextrin 6-glucohydrolase,
amylo-1,
6-glucosidase activity,
amylopectin 1,
6-glucosidase activity,
dextrin 6-alpha-D-glucosidase activity,
dextrin-1,6-glucosidase activity,
glycogen phosphorylase-limit dextrin alpha-1,6-glucohydrolase activity,
amylopectin 1,6-glucosidase activity,
dextrin-1,6-glucosidase activity,
glycogen phosphorylase-limit dextrin alpha-1,
6-glucohydrolase activity

Amylo-1,6-glucosidase deficiency results in the inability to degrade glycogen past its 1:4/1:6 branch points (hence called debrancher deficiency).
Only approximately 10% of glycogen stores are accessible before a branch point comes up.
Once a branch point is reached, glycogenolysis cannot proceed and hypoglycemia ensues.
Elevated lactate levels do not occur because glycolysis may proceed completely without a buildup of lactate.
Deposition of glycogen in the liver causes massive hepatomegaly, associated with marked elevations of liver enzymes with failure to thrive.
Because gluconeogenesis can occur effectively, hypoglycemia is not as severe as GSD-Ia and occurs only after more prolonged fasting.
There is not such an overdrive of counterregulatory hormones and so lipolysis is not constantly switched on and hyperlipidemia is not a feature.
Ketonuria occurs with prolonged fasting.

Long-term complications include severe muscle weakness and death from cardiomyopathy in those with muscle involvement.
Cirrhosis of the liver may occur, leading to liver failure.

Amylodextrin diagnosis is suspect in children with failure to thrive and massive hepatomegaly.
Unlike patients with GSD-Ia, those with GSD-III have marked elevation of AST and ALT.
Amylodextrin is no elevation of lactate with hypoglycemia and there is a rise in glucose in response to the fed glucagon stimulation test, but not in the fasted glucagon stimulation test (after a 6- to 8-hour fast).
Diagnosis may be made by enzymatic studies on liver biopsy or in white blood cells.
In addition to liver problems, about 33% to 50% patients have a myopathy resulting in muscle weakness and cardiomyopathy.
These children develop elevations in creatine kinase (CK) from 3 or 4 years on.

Treatment for the nonmyopathic form is frequent feeding and avoidance of overnight fasting by continuous glucose nasogastric feeding or nocturnal uncooked cornstarch therapy.
For those with myopathy, high-protein diet acts as a source of gluconeogenic substrate and may prevent the severe muscle wasting and cardiomyopathy.

The development of amylo-1,6-glucosidase activity is studied in fetal rat liver.
The activity of control fetuses is high on day 17.5, decreases from day 17.5 to day 19.5, and then rises during the next days.
In hypophysectomised fetuses, the increase of the activity is suppressed but not the decrease.
Moreover, if the mother is adrenalectomized the decrease and the increase are abolished in hypophysectomised fetuses.
Growth hormone administration is quite effective in preventing the decrease in enzyme activity but cortisol treatment does not prevent it.
Amylodextrin contrast, cortisol produces a precocious decrease of the activity in intact fetuses.
These findings suggest that during fetal life, two hormonal regulation mechanisms are involved in the regulation of amylo-1,6-glucosidase activity: cortisol has a repressive effect on the enzymic activity while growth hormone acts as an inducer.

In this study, we characterized the role of amylo-alpha-1,6-glucosidase (Aa16GL) in the biology and infectivity of Toxoplasma gondii, using Aa16GL-deficient parasites of type I RH and type II Prugniaud (Pru) strains.
The subcellular localization of Aa16GL protein was characterized by tagging a 3 × HA to the 3' end of the Aa16GL gene endogenous locus.
Immunostaining of the expressed Aa16GL protein revealed that it is located in several small cytoplasmic puncta.
Functional characterization of ΔAa16GL mutants using plaque assay, egress assay and intracellular replication assay showed that parasites lacking Aa16GL exhibit a slight reduction in the growth rate, but remained virulent to mice.
Although PruΔAa16GL tachyzoites retained the ability to differentiate into bradyzoites in vitro, they exhibited slight reduction in their ability to form cysts in mice.
Amylodextrin findings reveal new properties of Aa16GL and suggest that while it does not have a substantial role in mediating T. gondii infectivity, this protein can influence the formation of parasite cysts in mice.

Amylodextrin gene encodes the glycogen debrancher enzyme which is involved in glycogen degradation.
Amylodextrin enzyme has two independent catalytic activities which occur at different sites on the protein: a 4-alpha-glucotransferase activity and a amylo-1,6-glucosidase activity.
Mutations in this gene are associated with glycogen storage disease although a wide range of enzymatic and clinical variability occurs which may be due to tissue-specific alternative splicing.
Alternatively spliced transcripts encoding different isoforms have been described.

Glycogen debranching enzyme (GDE) has two enzymatic activities, 4-alpha-glucanotransferase and amylo-alpha-1,6-glucosidase. Products with 6-O-alpha-glucosyl structures formed from phosphorylase limit dextrin by the 4-alpha-glucanotransferase activity are hydrolyzed to glucose by the amylo-alpha-1,6-glucosidase activity.
Here, we probed the active site of amylo-alpha-1,6-glucosidase in porcine liver GDE using various 6-O-alpha-glucosyl-pyridylamino (PA)-maltooligosaccharides, with structures (Glcalpha1-4)(m)(Glcalpha1-6)Glcalpha1-4(Glcalpha1-4)(n)GlcPA (GlcPA, 1-deoxy-1-[(2-pyridyl)amino]-D-glucitol residue).
Fluorogenic dextrins were prepared from 6-O-alpha-glucosyl-alpha-, beta-, or gamma-cyclodextrin through partial acid hydrolysis, followed by fluorescent tagging of the reducing-end residues of the hydrolysates and separation by gel filtration and reversed-phase HPLC.
Porcine liver GDE hydrolyzed dextrins with the structure Glcalpha1-4(Glcalpha1-6)Glcalpha1-4Glc to glucose and the corresponding PA-maltooligosaccharides, whereas other dextrins were not hydrolyzed.
Amylodextrin, substrates must have two glucosyl residues sandwiching the isomaltosyl moiety to be hydrolyzed.
The rate of hydrolysis increased as m increased and reached maximum at m = 4. The rates were the highest when n = 1 but did not vary much with changes in n.
Of the dextrins examined, Glcalpha1-4Glcalpha1-4Glcalpha1-4Glcalpha1-4(Glcalpha1-6)Glcalpha1-4Glcalpha1-4GlcPA (6(3)-O-alpha-glucosyl-PA-maltoheptaose) was hydrolyzed most rapidly, suggesting that it fits the best in the amylo-alpha-1,6-glucosidase active site.
Amylodextrin is likely that the active site accommodates 6(2)-O-alpha-glucosyl-maltohexaose and that the interactions of seven glucosyl residues with the active site allow the most rapid hydrolysis of the alpha-1,6-glucosidic linkage of the isomaltosyl moiety.

Amylodextrin enzyme hydrolyzes an unsubstituted glucose unit linked by an alpha(1->6) bond to an alpha(1->4) glucose chain.
Amylodextrin enzyme activity found in mammals and Saccharomyces cerevisiae is in a polypeptide chain containing two active centers.
Amylodextrin other activity is similar to that of EC 2.4.1.25, which acts on the glycogen phosphorylase limit dextrin chains to expose the single glucose residues, which the 6-alpha-glucosidase activity can then hydrolyze.
Together, these two activities constitute the glycogen debranching system.

Synonyms: amylo-1,6-glucosidase, dextrin 6-α-D-glucosidase, amylopectin 1,6-glucosidase, dextrin-1,6-glucosidase, glycogen phosphorylase-limit dextrin α 1,6 glucohydrolase

Systematic Name: glycogen phosphorylase-limit dextrin 6-α-glucohydrolase

Unification Links: BRENDA:3.2.1.33, ENZYME:3.2.1.33, IUBMB-ExplorEnz:3.2.1.33

Reaction:a α-limit dextrin with short branches + H2O → a debranched α-limit dextrin + β-D-glucose

Unofficial Reactions:an α-limit dextrin + H2O → maltotetraose + a debranched α-limit dextrin

Catalysis of the hydrolysis of (1->6)-alpha-D-glucosidic branch linkages in glycogen phosphorylase limit dextrin.
Limit dextrin is the highly branched core that remains after exhaustive treatment of glycogen with glycogen phosphorylase.
Amylodextrin is formed because these enzymes cannot hydrolyze the (1->6) glycosidic linkages present.

The selection of a polymer for biomedical applications is a demanding task, given the large variety of available natural and synthetic polymers, often associated with structural and size heterogeneity.
The choice is dependent not only on the physicochemical and biochemical properties, but also on mandatory preclinical tests to insure safety.
Amylodextrin spite of the large availability of biodegradable polymers, the increasing demand continues to feed interest not only in the development of new materials, but also in improving the performance of the existing ones. Natural polymers are usually biodegradable and many of them offer excellent biocompatibility.
Amylodextrin polymers can be manipulated to produce different formulations such as capsules, hydrogels, or nanogels (hydrogel nanoparticles), meeting specifi c requirements such as—in the latest case—loading capacity, circulation time, and ability to accumulate in targeted pathological sites.
Starch is the most widespread and abundant storage carbohydrate in plants, cereal seeds (rice, maize, wheat, barley, sorghum, and others) representing the most important source, followed by tubers (e.g., potato, sweet potato, yam), roots (e.g., cassava, taro), and seeds of beans and peas.

Most native starches consist of two polymers of glucose, called amylose and amylopectin.
Amylose is mainly a linear chain composed of α-D-glycopyranose residues inked by α-1,4 glycosidic linkages.
Amylopectin molecule has the same structure as amylose but, in addition, contains α-1,6 glycosidic linkages at branching points.
Amylopectin is chemically similar to glycogen (the soluble polyglucan accumulated as a storage compound in animals, fungi, and bacteria) also a glucose polymer composed of α-1,4 linked and α-1,6 branched chains.
However, glycogen is more ramifi ed than amylopectin.
Starches from various botanical origins differ slightly in amylose content, chain-length distribution, molecular weight, and number of chains per cluster, among others.
The overall molecular features of starches, however, are more or less the same, all containing 10–20% amylose and 80–90% amylopectin.
Recently, several reviews reported the utilization of starch for biomedical purposes therefore, in this entry we will not address this subject.
Amylodextrin entry will instead be focused on the biomedical applications of starch derivative: dextrin

Reaction
Hydrolysis of (1right6)-alpha-D-glucosidic branch linkages in glycogen phosphorylase limit dextrin
Comments:
Amylodextrin enzyme hydrolyses an unsubstituted glucose unit linked by an α(1→6) bond to an α(1→4) glucose chain.
Amylodextrin enzyme activity found in mammals and yeast is in a polypeptide chain containing two active
Amylodextrin other activity is similar to that of EC 2.4.1.25 (4-α-glucanotransferase), which acts on the glycogen phosphorylase limit dextrin chains to expose the single glucose residues, which the 6-α-glucosidase activity can then hydrolyse. Together, these two activities constitute the glycogen debranching system.

Formation of amylo-1,6-glucosidase,4- a -glucanotransferase (AGL) mutants.
( A ) AGL mutants form aggresomes. Cells were transfected with HA-tagged AGL constructs for 12 h, and then 10 m M MG-132 was included

EC 3.2.1.33;
other name: dextrin 6‐α‐d‐glucosidase; an enzyme that catalyses the endohydrolysis of 1,6‐α‐d‐glucoside linkages at points of branching in chains of 1,4‐linked α‐d‐glucose residues.
The human enzyme also has glycogen debranching (4‐α‐glucanotransferase) activity.

Approved symbol : AGL
Approved name . amylo-alpha-1, 6-glucosidase, 4-alpha glucanotransferase
Locus type : gene with protein product
HGNC ID :HGNC:321
Symbol status: Approved
Previous names : amylo-1, 6-glucosidase, 4-alpha-glucanotransferase
Alias symbols :GDE
Alias names : glycogen debranching enzyme, glycogen storage disease type III
Chromosomal location : 1p21.2
Gene groups :Glycoside hydrolases

The AGL gene encodes the glycogen debrancher enzyme, a large monomeric protein with a molecular mass of approximately 160 kD.
The enzyme has 2 catalytic activities: amylo-1,6-glucosidase (EC 3.2.1.33) and 4-alpha-glucanotransferase.
The 2 activities are determined at separate catalytic sites on the polypeptide chain and can function independently of each other.
Both activities and glycogen binding are required for complete function.

Amylo-1,6-glucosidase or debranching enzyme is present in leucocytes of normal persons.
Amylodextrin activity is 50-100 times less than the leucocyte phosphorylase activity.
In leucocytes of patients with glycogen-storage disease due to deficiency of debranching enzyme, no amylo-1,6-glucosidase is found.

Entry : EC 3.2.1.33

Name:
amylo-alpha-1,6-glucosidase;
amylo-1,6-glucosidase;
dextrin 6-alpha-D-glucosidase;
amylopectin 1,6-glucosidase;
dextrin-1,6-glucosidase;
glycogen phosphorylase-limit dextrin alpha-1,6-glucohydrolase

Class:
Hydrolases;
Glycosylases;
Glycosidases, i.e. enzymes that hydrolyse O- and S-glycosyl compounds

Sysname:
glycogen phosphorylase-limit dextrin 6-alpha-glucohydrolase

Reaction(IUBMB) :
Hydrolysis of (1->6)-alpha-D-glucosidic branch linkages in glycogen phosphorylase limit dextrin

Reaction(KEGG):
(other) R02109 R06158(G)

Comment:
This enzyme hydrolyses an unsubstituted glucose unit linked by an alpha(1->6) bond to an alpha(1->4) glucose chain.
Amylodextrin enzyme activity found in mammals and yeast is in a polypeptide chain containing two active centres.
Amylodextrin other activity is similar to that of EC 2.4.1.25 (4-alpha-glucanotransferase), which acts on the glycogen phosphorylase limit dextrin chains to expose the single glucose residues, which the 6-alpha-glucosidase activity can then hydrolyse.
Together, these two activities constitute the glycogen debranching system.

History :
EC 3.2.1.33 created 1965, modified 2000

Orthology:
K01196 glycogen debranching enzyme

Genes:
HSA: 178(AGL)
PTR: 469392(AGL)
PPS: 100970156(AGL)
GGO: 101124513(AGL)
PON: 100462408(AGL)
NLE: 100607309(AGL)
MCC: 710910(AGL)
MCF: 102141897(AGL)
CSAB: 103224377(AGL)
CATY: 105590153(AGL)

AGL - Glycogen debranching enzyme; Multifunctional enzyme acting as 1,4-alpha-D-glucan:1,4- alpha-D-glucan 4-alpha-D-glycosyltransferase and amylo-1,6- glucosidase in glycogen degradation; Belongs to the glycogen debranching enzyme family

AGL - Glycogen debranching enzyme isoform X1; Derived by automated computational analysis using gene prediction method: Gnomon.
Supporting evidence includes similarity to: 10 Proteins, and 100% coverage of the annotated genomic feature by RNAseq alignments

An enzyme that catalyzes the hydrolysis of glycogen at specific branch points in its glucose residue chains; debrancher enzyme.

Phosphorylase and amylo-1,6-glucosidase catalyze the reversible reaction glucose-1-phosphate to glycogen.
Breast tissue abounds in both enzymes, in contrast to apocrine sweat glands, which have none.
Amylodextrin suggests that these two tissues have a profoundly different metabolic activity, even though breast tissue has been considered to be a modified apocrine sweat gland.

Amylo-alpha-1,6-glucosidase (AGL, EC 3.2.1.33) is one of the catalytic sites of the glycogen debrancher enzyme, which is encoded by the AGL gene.
Amylodextrin other catalytic activity is and 4-alpha-glucanotransferase (EC 2.4.1.25).
These enzymes are involved in glycogen degradation.
Mutations in the AGL gene are associated with glycogen storage disease.

Enzymes of glycogen debranching: Amylo-1,6-glucosidase (I) and oligo-1,4→1,4-glucantransferase (II):
Publisher Summary This chapter describes the specific oligosaccharide substrates for the separate measurement of each enzymatic activity (I and II).
Amylodextrin nature of the reaction catalyzed by II is demonstrated using these substrates.
Enzymes I and II act with phosphorylase to bring about the total degradation of glycogen to glucose 1-phosphate and glucose.
The amylo-l,6-glucosidase appears to act directly on a polysaccharide limit dextrin to form glucose from its outermost branch points.
The separate activity of amylo-l,6-glucosidase (I) is measured with certainty only when the substrate used is a branched oligosaccharide with the general structural features of B 5 .
A limit dextrin (LD) of glycogen may not be a specific substrate for (I), as the number of exposed branch point glucose residues in the LD is not known with certainty. Amylodextrin initial rate of glucose formation from an LD may depend only on the action of (I) and be independent of the prior action of (II).
Amylodextrin enzymatic activity of Oligo-l,4 → 1,4-glucantransferase (II) consists of the transfer of terminal maltosyl and, to a greater extent, maltotriosyl residues from α-l,4-1inkage in one chain to α-l,4-1inkage in another.
The reagents used, procedure followed, and the steps involved in the purification are also described in the chapter

The AGL gene provides instructions for making the glycogen debranching enzyme. This enzyme is involved in the breakdown of a complex sugar called glycogen, which is a major source of stored energy in the body. Glycogen is made up of several molecules of a simple sugar called glucose. Some glucose molecules are linked together in a straight line, while others branch off and form side chains. The glycogen debranching enzyme is involved in the breakdown of these side chains. The branched structure of glycogen makes it more compact for storage and allows it to break down more easily when it is needed for fuel.

Amylodextrin AGL gene provides instructions for making several different versions (isoforms) of the glycogen debranching enzyme.
These isoforms vary by size and are active (expressed) in different tissues.

Approximately 100 mutations in the AGL gene have been found to cause glycogen storage disease type III (also called GSDIII or Cori disease). Most of these mutations lead to a premature stop signal in the instructions for making the glycogen debranching enzyme, resulting in a nonfunctional enzyme.
As a result, the side chains of glycogen molecules cannot be removed and abnormal, partially broken down glycogen molecules are stored within cells. A buildup of abnormal glycogen damages organs and tissues throughout the body, particularly the liver and muscles, leading to the signs and symptoms of GSDIII.

Mutations in the AGL gene can affect different isoforms of the enzyme, depending on where the mutations are located in the gene.
For example, mutations that occur in a part of the AGL gene called exon 3 affect the isoform that is primarily expressed in the liver.
These mutations almost always lead to GSD type IIIb, which is characterized by liver problems.

Synonyms: amylo-1,6-glucosidase activity

Definition: Catalysis of the hydrolysis of (1->6)-alpha-D-glucosidic branch linkages in glycogen phosphorylase limit dextrin.
Limit dextrin is the highly branched core that remains after exhaustive treatment of glycogen with glycogen phosphorylase.
Amylodextrin is formed because these enzymes cannot hydrolyze the (1->6) glycosidic linkages present.

Parent Classes:
GO:0004133 - glycogen debranching enzyme activity,
GO:0090599 - alpha-glucosidase activity

Term Members:
limit dextrin α-1,6-glucohydrolase (glgX)Inferred from experiment,
glycogen debranching enzyme (AGL)

The assay of glycogen debranching activity by measurement of the release of glucose from phosphorylase limit dextrin (PLD), was originally used for assay of enzyme activity in muscle and liver tissue.
Results are corrected for the presence of nonspecific glucosidases by subtraction of the activity obtained with glycogen as substrate.
When assays are performed on muscle or liver, the activity obtained with glycogen is very low and its exact nature is not of practical importance.
Amylodextrin widespread use of blood cells and fibroblasts, in which the activity on glycogen is considerable, has prompted an examination of the apparent kinetic constants of this reaction.
In liver and muscle the apparent Km for PLD ranged from 0.5-2.0 mg/ml, whereas that for glycogen was lower by an order of magnitude.
The Vmax with glycogen as substrate did not exceed 20% of that with PLD. In leukocytes and platelets the Km for glycogen was higher than for PLD (0.1 and 0.5 mg/ml for PLD, 0.4 and 0.8 mg/ml for glycogen, in platelets and leukocytes, respectively), and the Vmax for PLD exceeded that for glycogen by 80%, In fibroblasts the Km for both PLD and glycogen was 1.5-3 mg/ml and the differences in Vmax were small.
These results indicate that substrate concentration should be varied according to the kinetic constants of each cell type and point to the importance of distinguishing between the (low?) activity of the debranching enzyme on glycogen and nonspecific hydrolysis.

General description
We are committed to bringing you Greener Alternative Products, which adhere to one or more of The 12 Principles of Greener Chemistry.
Amylodextrin product has been enhanced for energy efficiency and waste prevention when used in starch hydrolysis research.
For more information see the article in biofiles.

Application
α-glucosidase is used for the determination of α-amylase and the synthesis of various 1′-O-sucrose and 1-O-fructose esters.
Amylodextrin was also used in the measurement of glycosidase inhibition.
For the determination of α-amylase and the synthesis of various 1′-O-sucrose and 1-O-fructose esters

Packaging
100 units in glass bottle
1000 units in poly bottle
Sold on basis of p-nitrophenyl α-D-glucoside units.

Biochem/physiol Actions
α-glucosidase hydrolyzes carbohydrates by acting on 1,4-α linkages. Inhibition of α-glucosidase is a prominent target in the management of non-insulin-dependent diabetes mellitus.
Hydrolysis of terminal, non-reducing 1→4-linked D-glucose residues with release of D-glucose.

Unit Definition
One unit will liberate 1.0 μmole of D-glucose from p-nitrophenyl α-D-glucoside per min at pH 6.8 at 37 °C.

Analysis Note
Protein determined by biuret.

The affinity constant of amylo-1,6-glucosidase for glucose was determined in hemolyzed erythrocytes obtained from probable heterozygote carriers of glycogen storage disease type III, and from normal persons with high and low values of the enzyme.
A common Km was demonstrated in all cases, indicating that diminished enzyme activity may be caused by a reduced production of the normal enzyme (possibly coexistent with an inactive enzyme modification) or the presence of noncompetetive inhibitors.
No evidence for structural modifications of the enzyme in a normal population was obtained in this study.

CAS Number:9001-42-7
Enzyme Commission number:3.2.1.20 (BRENDA, IUBMB)
EC Number:232-604-7
MDL number:MFCD00081321
NACRES:NA.54

Glycogen Debranching Enzyme System" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings).
Descriptors are arranged in a hierarchical structure, which enables searching at various levels of specificity.

1,4-alpha-D-Glucan-1,4-alpha-D-glucan 4-alpha-D-glucosyltransferase/dextrin 6 alpha-D-glucanohydrolase.
Amylodextrin enzyme system having both 4-alpha-glucanotransferase (EC 2.4.1.25) and amylo-1,6-glucosidase (EC 3.2.1.33) activities.
Amylodextrin a transferase it transfers a segment of a 1,4-alpha-D-glucan to a new 4-position in an acceptor, which may be glucose or another 1,4-alpha-D-glucan.
Amylodextrin a glucosidase it catalyzes the endohydrolysis of 1,6-alpha-D-glucoside linkages at points of branching in chains of 1,4-linked alpha-D-glucose residues.
Amylo-1,6-glucosidase activity is deficient in glycogen storage disease type III.
Amylo-1,6-glucosidase , debranching enzyme (EC 3.2.1.33), an endoglucosidase that splits 1 → 6-glycosidic bonds at branching points of glycogen and amylopectin.
In mammals and yeast it is associated with a glycosyl transferase, which first removes all glucose residues above the 1 → 6 bond.
The complex found in muscle ( M r 237 kDa) consists of two subunits of M r 130 kDa, while the complex found in yeast ( M r 210 kDa) consists of three subunits of M r 120 kDa, 85 kDa and 70 kDa.

The localization of phosphorylase and amylo-1,6-glucosidase activity has been studied in surgical specimens of human skin from the palm, sole, axilla, external auditory meatus, and other representative regions of the body.
With few exceptions these enzymes are found in cells which are known to contain glycogen normally.
Amylodextrin epidermis shows some variability, but amylo-1,6-glucosidase is generally present in the stratum spinosum, while phosphorylase is found in both the stratum basale and the stratum spinosum.
The relative amounts of the enzymes vary with the thickness of the epidermis and with the age of the donor.
Growing hair follicles have abundant phosporylase and amylo-1,6-glucosidase in their outer root sheaths, while resting ones contain only phosphorylase.
A short portion of the epidermal duct of the eccrine sweat glands has no enzymatic activity, but the remainder of the duct and the secretory portion of the gland is richer in phosphorylase than any other structure of the skin.
Amylodextrin apocrine sweat glands have neither enzyme in their secretory coils, but the duct of these glands is rich in phosphorylase.
Time sebaceous glands contain both enzymes, but phosphorylase is more concentrated in the peripheral cells of the gland.
Neither the centers of the glands nor the sebum contain either enzyme.

Seven cases of glycogenosis type III (amylo-1, 6-glucosidase deficiency) in two probably related families from the Faroe Islands are presented.
The group of patients comprised two pairs of sibs.
In a total of 78 members of the two families case histories were obtained and clinical examinations, analyses of amylo-1, 6-glucosidase activity in erythrocytes and leucocytes, determinations of red cell, serum and enzyme groups as well as HL-A types were performed.
Amylodextrin addition, all patients were subjected to studies of liver function.
The distribution of patients in these families supports the assumption of autosomal recessive inheritance.
Heterozygotes could not be diagnosed with certainty by the methods of enzyme activity analysis employed.
The incidence of glycogenosis type III with amylo-1,6-glucosidase deficiency was found to be high in the Faroe Islands.

General description
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This product has been enhanced for energy efficiency and waste prevention when used in starch hydrolysis research.
For more information see the article in biofiles.

Packaging
100 units in glass bottle
1000 units in poly bottle
Sold on basis of p-nitrophenyl α-D-glucoside units.

Biochem/physiol Actions
α-glucosidase hydrolyzes carbohydrates by acting on 1,4-α linkages.
Inhibition of α-glucosidase is a prominent target in the management of non-insulin-dependent diabetes mellitus.
Hydrolysis of terminal, non-reducing 1→4-linked D-glucose residues with release of D-glucose.

Unit Definition
One unit will liberate 1.0 μmole of D-glucose from p-nitrophenyl α-D-glucoside per min at pH 6.8 at 37 °C.
Analysis Note
Protein determined by biuret.

An autosomal recessive metabolic disorder due to deficient expression of amylo-1,6-glucosidase (one part of the glycogen debranching enzyme system).
Amylodextrin clinical course of the disease is similar to that of glycogen storage disease type I, but milder.
Massive hepatomegaly, which is present in young children, diminishes and occasionally disappears with age.
Levels of glycogen with short outer branches are elevated in muscle, liver, and erythrocytes.
Six subgroups have been identified, with subgroups Type IIIa and Type IIIb being the most prevalent.

Andersen’s disease, also called Glycogenosis Type Iv, extremely rare hereditary metabolic disorder produced by absence of the enzyme amylo-1:4,1:6-transglucosidase, which is an essential mediator of the synthesis of glycogen.
An abnormal form of glycogen, amylopectin, is produced and accumulates in body tissues, particularly in the liver and heart.
Affected children appear normal at birth but fail to thrive and later lose muscle tone, becoming lethargic.
Amylodextrin liver and spleen become enlarged, and progressive liver failure occurs prior to death, usually before age three, caused by heart failure or bleeding from the esophagus.
Liver transplants have proved successful in treating the disorder.
Donated livers are often able to produce enough of the enzymes necessary to stop the accumulations of abnormal glycogen.
Andersen’s disease is transmitted as an autosomal-recessive trait, as are most similar enzyme defects.

A variety of functional studies has been employed to document the presence of type III glycogenosis and to distinguish it from type I.
Amylodextrin molecular defect is in the activity of amylo-1,6-glucosidase.
Amylodextrin overall reaction catalyzes the production of glucose from phosphorylase limit dextrin.
Amylodextrin partial reactions, transferase and glucosidase, appear to reside on a single polypeptide chain.
Hepatomegaly, hypoglycemia, late myopathy, storage of glycogen in liver and muscle, elevated transaminases and creatine phosphokinase, and deficient activity of the glycogen debranching enzyme amylo-1,6-glucosidase.
Activity of amylo-1,6-glucosidase was virtually absent in liver and muscle.
Amylodextrin history of the disease is impressive in that the nature of the disorder and the enzyme defect were worked out in studies on the index patient within a few years of the first report.
Amylodextrin enzyme has independent catalytic activities, glucosidase and transferase.

Amylodextrin development of amylo-1,6-glucosidase activity is studied in fetal rat liver.
Amylodextrin activity of control fetuses is high on day 17.5, decreases from day 17.5 to day 19.5, and then rises during the next days.
In hypophysectomised fetuses, the increase of the activity is suppressed but not the decrease.
Moreover, if the mother is adrenalectomized the decrease and the increase are abolished in hypophysectomised fetuses.
Growth hormone administration is quite effective in preventing the decrease in enzyme activity but cortisol treatment does not prevent it.
In contrast, cortisol produces a precocious decrease of the activity in intact fetuses.
These findings suggest that during fetal life, two hormonal regulation mechanisms are involved in the regulation of amylo-1,6-glucosidase activity: cortisol has a repressive effect on the enzymic activity while growth hormone acts as an inducer.

Description: Homo sapiens amylo-alpha-1, 6-glucosidase, 4-alpha-glucanotransferase (AGL), transcript variant 1, mRNA. (from RefSeq NM_000642)
RefSeq Summary (NM_000642): This gene encodes the glycogen debrancher enzyme which is involved in glycogen degradation.
This enzyme has two independent catalytic activities which occur at different sites on the protein: a 4-alpha-glucotransferase activity and a amylo-1,6-glucosidase activity.
Mutations in this gene are associated with glycogen storage disease although a wide range of enzymatic and clinical variability occurs which may be due to tissue-specific alternative splicing.
Alternatively spliced transcripts encoding different isoforms have been described.

Deficiency of amylo-1,6-glucosidase activity was expressed in parallel in liver and skin fibroblasts from a patient with type III glycogenosis.
In crude extracts of control liver and muscle, amylo-1,6-glucosidase (M.W. 164000) was identified by immunoprecipitation; no cross-reacting material was found in the patient's liver.
Assay of amylo-1,6-glucosidase activity in cultured skin fibroblasts from the affected family revealed less than 10 per cent of control value in mutant homozygous cells whereas in cells from the parents, activity was reduced to 40-60 per cent of the control value.
Activity in cultured amniotic fluid cells was similar to that of control fibroblasts.
In cultured amniotic fluid cells obtained during the mother's subsequent pregnancy, the normal amylo-1,6-glucosidase activity measured, predicted correctly the outcome of this pregnancy prior to the 20th week of gestation.

1 definition
The debranching enzyme is an enzyme that is involved in breaking down glycogen during glycogenolysis.

2 biochemistry
The debranching enzyme has two catalytic activities and functions as 4-α-glucanotransferase and amylo-α-1,6-glucosidase.

The glycogen phosphorylase breaks down a linear chain of glycogen with the release of glucose-1-phosphate down to 4 glucose units before the next 1,6-glycosidic branch.
The α (1,4) -> α (1,4) -glucan transferase activity of the debranching enzyme then transfers one trisaccharide unit from the remaining 4 glucose units to another chain.
This exposes the branch point.
The amylo-α-1,6-glucosidase activity of the debranching enzyme now hydrolytically cleaves the 1,6-glycosidic bond, which releases glucose.

3 pathophysiology
Various mutations in the gene that codes for the debranching enzyme are the cause of Forbes syndrome.
In this glycogen storage disease, the amylo-α-1,6-glucosidase activity is reduced, which leads to an accumulation of glycogen in the liver, kidneys and myocardium.

Introduction
Glycogenolysis is the biochemical pathway in which glycogen breaks down into glucose-1-phosphate and glycogen.
Amylodextrin reaction takes place in the hepatocytes and the myocytes.
Amylodextrin process is under the regulation of two key enzymes: phosphorylase kinase and glycogen phosphorylase.

Blood glucose is a source of energy for the entire human body.
During the fasting state, to maintain normal blood glucose levels, the liver plays a central role in producing glucose via glycogenolysis and gluconeogenesis.

Glycogen is a branched polysaccharide consisting of glucose units.
In humans,Amylodextrin is the principal storage form of glucose.
During times of need, the body breaks down glycogen to produce glucose.

Fundamentals
Glycogenolysis, along with glycolysis, plays a central role in carbohydrate metabolism.
Amylodextrin is the principal route of glycogen utilization.

Molecular
Glycogen is a storage polysaccharide consisting of D-glucose residues. The glucose residues are joined by α-1,4, which represent most of the linkages, and α-1,6 linkages, which constitute the branch points.
Together, they give the molecule a branched structure.
The advantages of the highly branched nature are the increased solubility and the ability to concentrate a larger molecule in a shorter space.
Function
The liver breaks down glycogen to maintain adequate blood glucose levels, whereas, muscles break down glycogen to maintain energy for contraction.

Glycogen debranching enzyme is one of the few known proteins possessing two independent catalytic activities that occur at separate sites on a single polypeptide chain.
Amylodextrin two activities are transferase and amylo-1,6-glucosidase.
Both the debranching enzyme and phosphorylase enzyme are necessary for the complete degradation of glycogen.

Adrenal hormones, such as catecholamines and glucocorticoids, regulate hepatic glycogenolysis. Adenosine stimulates hepatic glycogenolysis through the secretion of corticosterone from the adrenal glands.

By responding to norepinephrine, via a cAMP-dependent mechanism, glycogenolysis contributes to stability maintenance during hypoglycemia.
Glycogenolysis generates energy in the form of ATP, NADH, and lactate production.

Glycogenolysis is stimulated by glucagon, which is mediated by an intracellular increase of cAMP and Ca+2, which is mediated either by the adenylate cyclase or phospholipase C pathway.
Glucagon activates adenylate cyclase via GR2 receptors.
Adenylate cyclase converts ATP to cAMP, which activates PKA, which activates glycogenolysis enzymes via ATP-dependent phosphorylation.

Mechanism
Amylodextrin key regulatory enzymes of glycogenolysis are phosphorylase kinase and glycogen phosphorylase, both activated by phosphorylation.
These will predominantly express in the liver, muscle, and brain.

The process of glycogenolysis starts in the muscle due to the activity of the enzyme adenyl cyclase and cAMP.
cAMP then binds to phosphorylase kinase and converts it to its active form, which then converts phosphorylase b to phosphorylase a, which finally catalyzes the breakdown of glycogen.

Amylodextrin process of glycogen breakdown can occur either in the cytosol or in the lysosomes.
In the cytosol, the enzyme glycogen phosphorylase catalyzes the release of glucose-1-phosphate from the ends of glycogen branches with the use of inorganic phosphate to cleave α-1,4 bonds.
After that, glucose-1-phosphate can convert to glucose-6-phosphate.
In the lysosome, the enzyme acid α-glucosidase degrades lysosomal glycogen via an autophagy-dependent pathway.
Amylodextrin is known that the latter process serves as an immediate source of energy in the newborn period.

Since the enzyme phosphorylase can only cleave until it is four units from a branch point, when glycogen phosphorylase reaches a branch point that is four glucose residues away, the enzyme glycogen debranching enzyme transfers one of the branches to another chain, forming a new α-1,4 bond and leaving a single glucose unit at the branch point, which is later hydrolyzed by α-1,6-glucosidase, forming free glucose.

Clinical Significance
Von Gierke disease, also known as glycogen storage disease type 1A, is an autosomal recessive disorder in which the enzyme glucose-6-phosphatase is deficient, leading to an inability to break down glycogen into glucose.
Amylodextrin has an incidence of 1 in 100,000 live births.
Amylodextrin clinical presentation is characteristically an infant, usually at the age of three to six months (although the age of presentation is variable), presenting with hypoglycemia and hepatomegaly, frequently accompanied by hyperlipidemia, hyperuricemia, and lactic acidosis.
An enzyme assay and liver biopsy confirm the diagnosis.
Amylodextrin is manageable through adequate dietary therapy for preventing long-term complications.

Pompe disease, also known as glycogen storage disease type II or acid maltase deficiency, is an autosomal recessive disorder resulting from mutations in the GAA gene on chromosome 17q25, coding for acid alpha-glucosidase, leading to lysosomal accumulation of glycogen in various tissues, but mostly affecting cardiac and skeletal muscles.
Amylodextrin clinical presentation depends on the specific mutation and the resulting level of residual acid alpha-glucosidase activity.
Amylodextrin is classified depending on the timing of presentation: classic infantile-onset Pompe disease, with an age of onset ≤ 12 months and late-onset Pompe disease, which manifesting any time after 12 months of age.
The classic type characteristically demonstrates a rapidly progressive hypertrophic cardiomyopathy and left ventricular outflow obstruction, accompanied by muscle weakness, hypotonia, and respiratory distress.
Motor development is delayed.
Amylodextrin main cause of death is cardiac and respiratory failure, most commonly occurring before one year of age.
Amylodextrin late-onset type usually lacks cardiac involvement; it presents with muscle weakness progressing to profound weakness and wasting, eventually requiring a wheelchair.
Respiratory failure due to the involvement of the diaphragm is a common complication.

Cori Disease: also known as glycogen storage disease type III or limit dextrinosis, is a genetic disease caused by a mutation in the AGL gene located in the chromosome 1p21 encoding for glycogen debranching enzyme (amylo-1,6-glucosidase), leading to a deficient activity in the key enzyme responsible for glycogen degradation.
The characteristic clinical presentation is hypoglycemia, hyperlipidemia, growth retardation, and hepatomegaly.
Amylodextrin can subdivide into type IIIa, which present with hepatic and muscle involvement, that can develop myopathy and cardiomyopathy, and type IIIb, which primarily presents with liver disease.

McArdle disease: also known as glycogen storage disease type V or myophosphorylase deficiency, is an autosomal recessive inborn error of skeletal muscle metabolism in which glycogen phosphorylase activity is affected, resulting in an inability to break down glycogen.
Amylodextrin results from nonsense mutations in the PYGM-gene on chromosome 11, which codes for muscle glycogen-phosphorylase (myophosphorylase).
Since muscle glycogen-derived glucose is unavailable during exercise, and glycogen is the primary fuel in exercise, exercise intolerance characterizes the clinical scenario.
Vigorous exercise will often cause contractures and rhabdomyolysis accompanied by myoglobinuria.

Glycogenolysis activated by catecholamines, such as norepinephrine, has been implicated in memory consolidation.
Researchers have proposed that it is an important factor in the development of Alzheimer disease due to chronic atrophy.

Summary
The human diet contains 3 macronutrients that can be stored by the body as energy: carbohydrates (as the natural carbohydrate polymer glycogen, in mainly the liver and muscle), protein (as muscle, the natural protein source of the body) and fat (in organs and fat tissue).
There are at least 13 glycogen storage disease (GSD) subtypes, in which the energy stored as glycogen cannot be adequately produced or broken down.
The liver GSD subtypes cause fasting intolerance (types 0, Ia, Ib, III, VI, IX and XI) or liver failure (type IV), with or without muscle symptoms.
The fasting induced low blood glucose concentrations decrease the energy supply by the liver to organs like the brain.

Amylodextrin ketotic GSD subtypes 0, III, VI, IX, and XI are associated with fasting ketotic hypoglycemia.
In these patients, the breakdown of glycogen (glycogenolysis) is defective.
Their fasting intolerance is considered relatively mild compared to GSD type I patients, in whom both glycogenolysis and the generation of glucose from non-carbohydrate substances (gluconeogenesis) are impaired.

Amylodextrin is the purpose of this communication to present a case of hepatomegaly in a Negro girl who was subsequently shown to suffer from glycogen-storage disease.
Amylodextrin definite diagnosis was made with the help of repeated glucagon tolerance tests, galactose tolerance test, microscopical tissue examination and biochemical tissue analysis.
Thus, this was classified as a case of amylo-1.6-glucosidase deficiency, also known as Cori's disease, since Cori1 discovered this metabolic disorder and defined its enzymatic defect.

MUSCLE phosphofructokinase (PFK) deficiency in man was first described by Tauri et al1 in a biochemical investigation in 1965. In 1967, Layzer et al2 reported additional biochemical and immunologic studies in a second family with this disease. This disorder may be regarded as a fourth type of muscle glycogenosis3 in addition to deficiencies of phosphorylase, amylo-1,6-glucosidase (debrancher) and amylo-1,4-glucosidase (acid maltase).

Amylodextrin PFK catalyzes the conversion of fructose-6-phosphate (F-6-P) to fructose-1,6-diphosphate (F-1,6-PP); in the absence of this enzyme, glycogen cannot be broken down to lactic acid (Fig 1).
The clinical features of this disease are identical to muscle phosphorylase deficiency (McArdle's disease) and include muscle cramps, exercise intolerance, contracture following ischemic work, and myoglobinuria.