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Glycoside Hydrolase Family 15
In molecular biology, glycoside hydrolase family 15 is a family of glycoside hydrolases. Glycoside hydrolases are a widespread group of enzymes that hydrolyse the glycosidic bond between two or more carbohydrates, or between a carbohydrate and a non-carbohydrate moiety. A classification system for glycoside hydrolases, based on sequence similarity, has led to the definition of >100 different families. This classification is available on the CAZy web site, and also discussed at CAZypedia, an online encyclopedia of carbohydrate active enzymes. y _ Glycoside hydrolase family 1CAZY GH_15comprises enzymes with several known activities; glucoamylase (); alpha-glucosidase (); glucodextranase (). Glucoamylase (GA) catalyses the release of D-glucose from the non-reducing ends of starch and other oligo- or poly-saccharides. Studies of fungal GA have indicated 3 closely clustered acidic residues that play a role in the catalytic mechanism. This region is also conserved in a recently sequenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Family
A protein family is a group of evolutionarily related proteins. In many cases, a protein family has a corresponding gene family, in which each gene encodes a corresponding protein with a 1:1 relationship. The term "protein family" should not be confused with family as it is used in taxonomy. Proteins in a family descend from a common ancestor and typically have similar three-dimensional structures, functions, and significant sequence similarity. The most important of these is sequence similarity (usually amino-acid sequence), since it is the strictest indicator of homology and therefore the clearest indicator of common ancestry. A fairly well developed framework exists for evaluating the significance of similarity between a group of sequences using sequence alignment methods. Proteins that do not share a common ancestor are very unlikely to show statistically significant sequence similarity, making sequence alignment a powerful tool for identifying the members of protein families ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrasaccharide
A tetrasaccharide is a carbohydrate which gives upon hydrolysis four molecules of the same or different monosaccharides. For example, stachyose upon hydrolysis gives one molecule each of glucose and fructose and two molecules of galactose Galactose (, '' galacto-'' + '' -ose'', "milk sugar"), sometimes abbreviated Gal, is a monosaccharide sugar that is about as sweet as glucose, and about 65% as sweet as sucrose. It is an aldohexose and a C-4 epimer of glucose. A galactose molec .... The general formula of a tetrasaccharide is typically C24H42O21. References {{organic-chem-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta Strand
The beta sheet, (β-sheet) (also β-pleated sheet) is a common motif of the regular protein secondary structure. Beta sheets consist of beta strands (β-strands) connected laterally by at least two or three backbone hydrogen bonds, forming a generally twisted, pleated sheet. A β-strand is a stretch of polypeptide chain typically 3 to 10 amino acids long with backbone in an extended conformation. The supramolecular association of β-sheets has been implicated in the formation of the fibrils and protein aggregates observed in amyloidosis, notably Alzheimer's disease. History The first β-sheet structure was proposed by William Astbury in the 1930s. He proposed the idea of hydrogen bonding between the peptide bonds of parallel or antiparallel extended β-strands. However, Astbury did not have the necessary data on the bond geometry of the amino acids in order to build accurate models, especially since he did not then know that the peptide bond was planar. A refined version w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha Helices
The alpha helix (α-helix) is a common motif in the secondary structure of proteins and is a right hand-helix conformation in which every backbone N−H group hydrogen bonds to the backbone C=O group of the amino acid located four residues earlier along the protein sequence. The alpha helix is also called a classic Pauling–Corey–Branson α-helix. The name 3.613-helix is also used for this type of helix, denoting the average number of residues per helical turn, with 13 atoms being involved in the ring formed by the hydrogen bond. Among types of local structure in proteins, the α-helix is the most extreme and the most predictable from sequence, as well as the most prevalent. Discovery In the early 1930s, William Astbury showed that there were drastic changes in the X-ray fiber diffraction of moist wool or hair fibers upon significant stretching. The data suggested that the unstretched fibers had a coiled molecular structure with a characteristic repeat of ≈. Astbu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angstrom
The angstromEntry "angstrom" in the Oxford online dictionary. Retrieved on 2019-03-02 from https://en.oxforddictionaries.com/definition/angstrom.Entry "angstrom" in the Merriam-Webster online dictionary. Retrieved on 2019-03-02 from https://www.merriam-webster.com/dictionary/angstrom. (, ; , ) or ångström is a metric unit of length equal to m; that is, one ten-billionth ( US) of a metre, a hundred-millionth of a centimetre,Entry "angstrom" in the Oxford English Dictionary, 2nd edition (1986). Retrieved on 2021-11-22 from https://www.oed.com/oed2/00008552. 0.1 nanometre, or 100 picometres. Its symbol is Å, a letter of the Swedish alphabet. The unit is named after the Swedish physicist Anders Jonas Ångström (1814–1874). The angstrom is often used in the natural sciences and technology to express sizes of atoms, molecules, microscopic biological structures, and lengths of chemical bonds, arrangement of atoms in crystals,Arturas Vailionis (2015):Geometry of Crystals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspergillus Awamori
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''Aspergillus awamori'' is a species of aspergillus that is used to make awamori and shōchū. It can produce citric acid and convert starch to sugar. ''Aspergillus awamori'' is often confused with ''Aspergillus niger'' as they have very similar morphologies and growth rates at different temperatures, and produce several common. In 1901, Tamaki Inui, lecturer at University of Tokyo succeeded in the first isolating and culturing. In 1910, Genichiro Kawachi succeeded for the first time in cultivating var. kawachi, a variety of subtaxa of ''A. awamori''. This improved the efficiency of shōchū production. See also * ''Aspergillus luchuensis'' - also known as ''Aspergillus awamori'' var. ''kawachi'' References awamori ''Awamori'' (, Okinawan: , āmui'') is an alcoholic beverage indigenous and unique to Okinawa, Japan. It is made from long grain indica rice, and is not a direct product of brewing (like ''sake'') but of distillation (like ''shōchū''). The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acarbose
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 (Bayer AG), in North America as Precose ( Bayer Pharmaceuticals), and in Canada as Prandase (Bayer AG). It is cheap and popular in China, but not in the U.S. One physician explains the use in the U.S. is limited because it is not potent enough to justify the side effects of diarrhea and flatulence. However, a recent large study concludes "acarbose is effective, safe and well tolerated in a large cohort of Asian patients with type 2 diabetes." A possible explanation for the differing opinions is an observation that acarbose is significantly more effective in patients eating a relatively high carbohydrate Eastern diet. It is a starch blocker, and inhibits alpha glucosidase, an intestinal enzyme that releases glucose from larger carbohydrates. It is composed of an acarviosin moiety with a maltose at the reducing term ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fungal
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from the other eukaryotic kingdoms, which by one traditional classification include Plantae, Animalia, Protozoa, and Chromista. A characteristic that places fungi in a different kingdom from plants, bacteria, and some protists is chitin in their cell walls. Fungi, like animals, are heterotrophs; they acquire their food by absorbing dissolved molecules, typically by secreting digestive enzymes into their environment. Fungi do not photosynthesize. Growth is their means of mobility, except for spores (a few of which are flagellated), which may travel through the air or water. Fungi are the principal decomposers in ecological systems. These and other differences place fungi in a single group of related organisms, named the ''Eumycota'' (''true f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycoside Hydrolase
Glycoside hydrolases (also called glycosidases or glycosyl hydrolases) catalyze the hydrolysis of glycosidic bonds in complex sugars. They are extremely common enzymes with roles in nature including degradation of biomass such as cellulose (cellulase), hemicellulose, and starch (amylase), in anti-bacterial defense strategies (e.g., lysozyme), in pathogenesis mechanisms (e.g., viral neuraminidases) and in normal cellular function (e.g., trimming mannosidases involved in N-linked glycoprotein biosynthesis). Together with glycosyltransferases, glycosidases form the major catalytic machinery for the synthesis and breakage of glycosidic bonds. Occurrence and importance Glycoside hydrolases are found in essentially all domains of life. In prokaryotes, they are found both as intracellular and extracellular enzymes that are largely involved in nutrient acquisition. One of the important occurrences of glycoside hydrolases in bacteria is the enzyme beta-galactosidase (LacZ), which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
D-glucose
Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, using energy from sunlight, where it is used to make cellulose in cell walls, the most abundant carbohydrate in the world. In energy metabolism, glucose is the most important source of energy in all organisms. Glucose for metabolism is stored as a polymer, in plants mainly as starch and amylopectin, and in animals as glycogen. Glucose circulates in the blood of animals as blood sugar. The naturally occurring form of glucose is -glucose, while -glucose is produced synthetically in comparatively small amounts and is less biologically active. Glucose is a monosaccharide containing six carbon atoms and an aldehyde group, and is therefore an aldohexose. The glucose molecule can exist in an open-chain (acyclic) as well as ring (cyclic) form. Glucos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-glucosidase
α-Glucosidase (EC 3.2.1.20, maltase, glucoinvertase, glucosidosucrase, maltase-glucoamylase, α-glucopyranosidase, glucosidoinvertase, α-D-glucosidase, α-glucoside hydrolase, α-1,4-glucosidase, α-D-glucoside glucohydrolase; systematic name α-D-glucoside glucohydrolase) is a glucosidase located in the brush border of the small intestine that acts upon α(1→4) bonds: : Hydrolysis of terminal, non-reducing (1→4)-linked α-D-glucose residues with release of D-glucose This is in contrast to β-glucosidase. α-Glucosidase breaks down starch and disaccharides to glucose. Other glucosidases include: * Cellulase * Beta-glucosidase * Debranching enzyme Mechanism α-Glucosidase hydrolyzes terminal non-reducing (1→4)-linked α-glucose residues to release a single α-glucose molecule. α-Glucosidase is a carbohydrate-hydrolase that releases α-glucose as opposed to β-glucose. β-Glucose residues can be released by glucoamylase, a functionally similar enzyme. The sub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
