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β-1,3-glucanase
Glucanases are enzymes that break down large polysaccharides via hydrolysis. The product of the hydrolysis reaction is called a glucan, a linear polysaccharide made of up to 1200 glucose monomers, held together with glycosidic bonds. Glucans are abundant in the endosperm cell walls of cereals such as barley, rye, sorghum, rice, and wheat. Glucanases are also referred to as lichenases, hydrolases, glycosidases, glycosyl hydrolases, and/or laminarinases. Many types of glucanases share similar amino acid sequences but vastly different substrates. Of the known endo-glucanases, 1,3-1,4-β-glucanase is considered the most active. Structure β-glucanases The secondary and tertiary structures of β-glucanases involves the stacking of multiple β-sheets, each of which are made of several anti-parallel strands that bend and form a cleft crossing the active site of the enzyme. This type of structure has been called the "jelly roll fold." Some common β-glucanases * 1,3-β-glucanas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endo-1,3(4)-b-glucanase
Endo-1,3(4)-β-glucanase (EC 3.2.1.6, endo-1,3-β-D-glucanase, laminarinase, β-1,3-glucanase,4-glucanase, endo-β-(1→3)-D-glucanase, endo-1,3-1,4-β-D-glucanase, endo-β-(1-3)-D-glucanase, endo-β-1,3-glucanase IV, 1,3-1,4)-β-D-glucan 3(4)-glucanohydrolase) is an enzyme with systematic name 3(or 4)-β-D-glucan 3(4)-glucanohydrolase. It catalyses the following chemical reaction : Endohydrolysis of (1→3)- or (1→4)-linkages in β-D-glucans when the glucose residue whose reducing group is involved in the linkage to be hydrolysed is itself substituted at C-3 Substrates include laminarin, lichenin Lichenin, also known as lichenan or moss starch, is a complex glucan occurring in certain species of lichens. It can be extracted from ''Cetraria islandica'' (Iceland moss). It has been studied since about 1957. Structure Chemically, lichenin i ... and cereal D- glucans. References External links * {{Portal bar, Biology, border=no EC 3.2.1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Callose
Callose is a plant polysaccharide. Its production is due to the glucan synthase-like gene (GLS) in various places within a plant. It is produced to act as a temporary cell wall in response to stimuli such as stress or damage. Callose is composed of glucose residues linked together through β-1,3-linkages, and is termed a β-glucan. It is thought to be manufactured at the cell wall by callose synthases and is degraded by β-1,3-glucanases. Callose is very important for the permeability of plasmodesmata (Pd) in plants; the plant's permeability is regulated by plasmodesmata callose (PDC). PDC is made by callose synthases and broken down by β-1,3-glucanases (BGs). The amount of callose that is built up at the plasmodesmatal neck, which is brought about by the interference of callose synthases (CalSs) and β-1,3-glucanases, determines the conductivity of the plasmodesmata. Formation and function Callose is laid down at plasmodesmata, at the cell plate during cytokinesis, and during po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
β-1,3-glucanase
Glucanases are enzymes that break down large polysaccharides via hydrolysis. The product of the hydrolysis reaction is called a glucan, a linear polysaccharide made of up to 1200 glucose monomers, held together with glycosidic bonds. Glucans are abundant in the endosperm cell walls of cereals such as barley, rye, sorghum, rice, and wheat. Glucanases are also referred to as lichenases, hydrolases, glycosidases, glycosyl hydrolases, and/or laminarinases. Many types of glucanases share similar amino acid sequences but vastly different substrates. Of the known endo-glucanases, 1,3-1,4-β-glucanase is considered the most active. Structure β-glucanases The secondary and tertiary structures of β-glucanases involves the stacking of multiple β-sheets, each of which are made of several anti-parallel strands that bend and form a cleft crossing the active site of the enzyme. This type of structure has been called the "jelly roll fold." Some common β-glucanases * 1,3-β-glucanas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xyloglucan-specific Exo-beta-1,4-glucanase
In enzymology, a xyloglucan-specific exo-beta-1,4-glucanase () is an enzyme that catalyzes the chemical reaction :xyloglucan + H2O \rightleftharpoons xyloglucan oligosaccharides (exohydrolysis of 1,4-beta-D-glucosidic linkages in xyloglucan) Thus, the two substrates of this enzyme are xyloglucan and H2O, and its products are xyloglucan oligosaccharides ( exohydrolysis of 1,4-beta-D-glucosidic linkages in xyloglucan). This enzyme belongs to the family of hydrolases, specifically those glycosidases that hydrolyse O- and S-glycosyl compounds. The systematic name A systematic name is a name given in a systematic way to one unique group, organism, object or chemical substance, out of a specific population or collection. Systematic names are usually part of a nomenclature. A semisystematic name or semitrivial ... of this enzyme class is 6)-alpha-D-xylo.html" ;"title="1->6)-alpha-D-xylo">1->6)-alpha-D-xylo(1->4)-beta-D-glucan exo-glucohydrolase. This enzyme is also called Cel74 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xyloglucan-specific Endo-beta-1,4-glucanase
In enzymology, a xyloglucan-specific endo-beta-1,4-glucanase () is an enzyme that catalyzes the chemical reaction :xyloglucan + H2O \rightleftharpoons xyloglucan oligosaccharides Thus, the two substrates of this enzyme are xyloglucan and H2O, whereas its product is xyloglucan oligosaccharides. This enzyme belongs to the family of hydrolases, specifically those glycosidases that hydrolyse O- and S-glycosyl compounds. The systematic name of this enzyme class is 6)-alpha-D-xylo.html" ;"title="1->6)-alpha-D-xylo">1->6)-alpha-D-xylo(1->4)-beta-D-glucan glucanohydrolase. Other names in common use include XEG, xyloglucan endo-beta-1,4-glucanase, xyloglucanase, xyloglucanendohydrolase, XH, and 1,4-beta-D-glucan glucanohydrolase. Family 12 was first identified in plant pathogens by discovery in ''Phytophthora'' spp. Structural studies As of late 2007, 15 structures A structure is an arrangement and organization of interrelated elements in a material object or system, or the o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Î’-D-glucan
Beta-glucans, β-glucans comprise a group of β-D-glucose polysaccharides ( glucans) naturally occurring in the cell walls of cereals, bacteria, and fungi, with significantly differing physicochemical properties dependent on source. Typically, β-glucans form a linear backbone with 1–3 β-glycosidic bonds but vary with respect to molecular mass, solubility, viscosity, branching structure, and gelation properties, causing diverse physiological effects in animals. At dietary intake levels of at least 3 g per day, oat fiber β-glucan decreases blood levels of LDL cholesterol and so may reduce the risk of cardiovascular diseases. β-glucans are natural gums and are used as texturing agents in various nutraceutical and cosmetic products, and as soluble fiber supplements. History Cereal and fungal products have been used for centuries for medicinal and cosmetic purposes; however, the specific role of β-glucan was not explored until the 20th century. β-glucans were first d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lichenin
Lichenin, also known as lichenan or moss starch, is a complex glucan occurring in certain species of lichens. It can be extracted from ''Cetraria islandica'' (Iceland moss). It has been studied since about 1957. Structure Chemically, lichenin is a mixed-linkage glucan, consisting of repeating glucose units linked by β-1,3 and β-1,4 glycosidic bonds. Uses It is an important carbohydrate for reindeers and northern flying squirrels, which eat the lichen ''Bryoria fremontii''. It can be extracted by digesting Iceland moss in a cold, weak solution of sodium bicarbonate, carbonate of soda for some time, and then boiling. By this process the lichenin is dissolved and on cooling separates as a colorless jelly. Iodine imparts no color to it. Other uses of the name In his 1960 novel ''Trouble with Lichen'', John Wyndham gives the name ''Lichenin'' to a biochemical extract of lichen used to extend life expectancy beyond 300 years. References Polysaccharides Lichen products ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellulose
Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wall of green plants, many forms of algae and the oomycetes. Some species of bacteria secrete it to form biofilms. Cellulose is the most abundant organic polymer on Earth. The cellulose content of cotton fiber is 90%, that of wood is 40–50%, and that of dried hemp is approximately 57%. Cellulose is mainly used to produce paperboard and paper. Smaller quantities are converted into a wide variety of derivative products such as cellophane and rayon. Conversion of cellulose from energy crops into biofuels such as cellulosic ethanol is under development as a renewable fuel source. Cellulose for industrial use is mainly obtained from wood pulp and cotton. Some animals, particularly ruminants and termites, can digest cellulose with the help of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellulase
Cellulase (EC 3.2.1.4; systematic name 4-β-D-glucan 4-glucanohydrolase) is any of several enzymes produced chiefly by fungi, bacteria, and protozoans that catalyze cellulolysis, the decomposition of cellulose and of some related polysaccharides: : Endohydrolysis of (1→4)-β-D-glucosidic linkages in cellulose, lichenin and cereal β-D-glucan The name is also used for any naturally occurring mixture or complex of various such enzymes, that act serially or synergistically to decompose cellulosic material. Cellulases break down the cellulose molecule into monosaccharides ("simple sugars") such as β-glucose, or shorter polysaccharides and oligosaccharides. Cellulose breakdown is of considerable economic importance, because it makes a major constituent of plants available for consumption and use in chemical reactions. The specific reaction involved is the hydrolysis of the 1,4-β-D-glycosidic linkages in cellulose, hemicellulose, lichenin, and cereal β-D-glucans. Because cell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Î’-1,6-glucan
Beta-glucans, β-glucans comprise a group of β-D-glucose polysaccharides ( glucans) naturally occurring in the cell walls of cereals, bacteria, and fungi, with significantly differing physicochemical properties dependent on source. Typically, β-glucans form a linear backbone with 1–3 β-glycosidic bonds but vary with respect to molecular mass, solubility, viscosity, branching structure, and gelation properties, causing diverse physiological effects in animals. At dietary intake levels of at least 3 g per day, oat fiber β-glucan decreases blood levels of LDL cholesterol and so may reduce the risk of cardiovascular diseases. β-glucans are natural gums and are used as texturing agents in various nutraceutical and cosmetic products, and as soluble fiber supplements. History Cereal and fungal products have been used for centuries for medicinal and cosmetic purposes; however, the specific role of β-glucan was not explored until the 20th century. β-glucans were first d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
