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β-1,3-glucanase
Glucanases are enzymes that break down lucanspolysaccharides via hydrolysis. The product of the hydrolysis reaction are smaller glucans, a linear or branched polysaccharide made of up to 1200 glucose monomers, linked by 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-gluc ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endo-1,3(4)-β-glucanase
Endo-1,3(4)-β-glucanase (, 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 and cereal D-glucan A glucan is a polysaccharide derived from D-glucose, linked by glycosidic bonds. Glucans are noted in two forms: alpha glucans and beta glucans. Many beta-glucans are medically important. They represent a drug target for antifungal medications of ...s. References External links * {{Portal bar, Biology, border=no EC 3.2.1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
β-1,3-glucanase
Glucanases are enzymes that break down lucanspolysaccharides via hydrolysis. The product of the hydrolysis reaction are smaller glucans, a linear or branched polysaccharide made of up to 1200 glucose monomers, linked by 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-gluc ... [...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 disco ... [...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 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 John Wyndham Parkes Lucas Beynon Harris (; 10 July 1903 – 11 March 1969) was an English science fiction writer best known for his works published under the pen na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellulose
Cellulose is an organic compound with the chemical formula, formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of glycosidic bond, β(1→4) linked glucose, 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 biopolymer, organic polymer on Earth. The cellulose content of cotton fibre 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. Cellulose is also greatly affected by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellulase
Cellulase (; 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 beta-D-glucan, β-D-glucans. Because ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
β-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 disco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
