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Sarsasapogenin 3β-glucosyltransferase
In enzymology, a sarsasapogenin 3β-glucosyltransferase () is an enzyme that Catalysis, catalyzes the chemical reaction :UDP-glucose + sarsasapogenin UDP + sarsasapogenin 3-''O''-β-D-glucoside Thus, the two Substrate (biochemistry), substrates of this enzyme are UDP-glucose and sarsasapogenin [(3β,5β,25''S'')-spirostan-3-ol], whereas its two Product (chemistry), products are Uridine diphosphate, UDP and sarsasapogenin 3-''O''-β-D-glucoside. The enzyme was first isolated from the root of the common asparagus (''Asparagus officinalis''). It is specific for substrate sterols with the uncommon 5β-configuration (sarsasapogenin and smilagenin), that is with a ''cis''-linkage between the A and B rings of the steroid nucleus. This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The List of enzymes, systematic name of this enzyme class is UDP-glucose:(3β,5β,25''S'')-spirostan-3-ol 3-''O''-β-D-glucosyltransferase. This enzyme is also c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzymology
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecules known as product (chemistry), products. Almost all metabolism, metabolic processes in the cell (biology), cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme, pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts include Ribozyme, catalytic RNA molecules, also called ribozymes. They are sometimes descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catalysis
Catalysis () is the increase in rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quickly, very small amounts of catalyst often suffice; mixing, surface area, and temperature are important factors in reaction rate. Catalysts generally react with one or more reactants to form intermediates that subsequently give the final reaction product, in the process of regenerating the catalyst. The rate increase occurs because the catalyst allows the reaction to occur by an alternative mechanism which may be much faster than the noncatalyzed mechanism. However the noncatalyzed mechanism does remain possible, so that the total rate (catalyzed plus noncatalyzed) can only increase in the presence of the catalyst and never decrease. Catalysis may be classified as either homogeneous, whose components are dispersed in the same phase (usual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Reaction
A chemical reaction is a process that leads to the chemistry, chemical transformation of one set of chemical substances to another. When chemical reactions occur, the atoms are rearranged and the reaction is accompanied by an Gibbs free energy, energy change as new products are generated. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the Atomic nucleus, nuclei (no change to the elements present), and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive Chemical element, elements where both electronic and nuclear changes can occur. The substance (or substances) initially involved in a chemical reaction are called reagent, reactants or reagents. Chemical reactions are usually characterized by a chemical change, and they yield one or more Product (c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Substrate (biochemistry)
In chemistry, the term substrate is highly context-dependent. Broadly speaking, it can refer either to a chemical species being observed in a chemical reaction, or to a surface on which other chemical reactions or microscopy are performed. In the former sense, a reagent is added to the ''substrate'' to generate a product through a chemical reaction. The term is used in a similar sense in synthetic and organic chemistry, where the substrate is the chemical of interest that is being modified. In biochemistry, an enzyme substrate is the material upon which an enzyme acts. When referring to Le Chatelier's principle, the substrate is the reagent whose concentration is changed. ;Spontaneous reaction : :*Where S is substrate and P is product. ;Catalysed reaction : :*Where S is substrate, P is product and C is catalyst. In the latter sense, it may refer to a surface on which other chemical reactions are performed or play a supporting role in a variety of spectroscopic and mic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UDP-glucose
Uridine diphosphate glucose (uracil-diphosphate glucose, UDP-glucose) is a nucleotide sugar. It is involved in glycosyltransferase reactions in metabolism. Functions UDP-glucose is used in nucleotide sugar metabolism as an activated form of glucose, a substrate for enzymes called glucosyltransferases. UDP-glucose is a precursor of glycogen and can be converted into UDP-galactose and UDP-glucuronic acid, which can then be used as substrates by the enzymes that make polysaccharides containing galactose and glucuronic acid. UDP-glucose can also be used as a precursor of sucrose, lipopolysaccharides and glycosphingolipids. Components UDP-glucose consists of the pyrophosphate group, ribose, glucose, and uracil. See also * DNA * Nucleoside * Nucleotide * Oligonucleotide * RNA * TDP-glucose * Uracil Uracil () (nucleoside#List of nucleosides and corresponding nucleobases, symbol U or Ura) is one of the four nucleotide bases in the nucleic acid RNA. The others are adenine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sarsasapogenin
Sarsasapogenin is a steroidal sapogenin, that is the aglycosidic portion of a plant saponin. It is named after sarsaparilla (''Smilax'' sp.),. a family of climbing plants found in subtropical regions. It was one of the first sapogenins to be identified, and the first spirostan steroid to be identified as such.. The identification of the spirostan structure, with its ketone spiro acetal functionality, was fundamental in the development of the Marker degradation, which allowed the industrial production of progesterone and other sex hormones from plant steroids. Sarsasapogenin is unusual in that it has a ''cis''-linkage between rings A and B of the steroid nucleus, as opposed to the more usual ''trans''-linkage found in other saturated steroids. This 5β configuration is biologically significant, as a specific enzyme – sarsasapogenin 3β-glucosyltransferase – is found in several plants for the glycosylation of sarsasapogenin. The (''S'')-configuration at C-25 is also in contras ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Product (chemistry)
Products are the species formed from chemical reactions. During a chemical reaction, reactants are transformed into products after passing through a high energy transition state. This process results in the consumption of the reactants. It can be a spontaneous reaction or mediated by catalysts which lower the energy of the transition state, and by solvents which provide the chemical environment necessary for the reaction to take place. When represented in chemical equations, products are by convention drawn on the right-hand side, even in the case of reversible reactions. The properties of products such as their energies help determine several characteristics of a chemical reaction, such as whether the reaction is exergonic or endergonic. Additionally, the properties of a product can make it easier to extract and purify following a chemical reaction, especially if the product has a different state of matter than the reactants. Spontaneous reaction : R \rightarrow P *W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uridine Diphosphate
Uridine diphosphate, abbreviated UDP, is an organic compound. It is an ester of pyrophosphoric acid with the nucleoside uridine. UDP consists of the pyrophosphate group, the pentose sugar ribose, and the nucleobase uracil. UDP is an important factor in glycogenesis. Before glucose can be stored as glycogen in the liver and muscles, the enzyme UDP-glucose pyrophosphorylase forms a UDP-glucose unit by combining glucose 1-phosphate with uridine triphosphate, cleaving a pyrophosphate ion in the process. Then, the enzyme glycogen synthase combines UDP-glucose units to form a glycogen chain. The UDP molecule is cleaved from the glucose ring during this process and can be reused by UDP-glucose pyrophosphorylase. See also * DNA * Nucleoside * Nucleotide * Oligonucleotide * RNA Ribonucleic acid (RNA) is a polymeric molecule that is essential for most biological functions, either by performing the function itself (non-coding RNA) or by forming a template for the production of prote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asparagus
Asparagus (''Asparagus officinalis'') is a perennial flowering plant species in the genus ''Asparagus (genus), Asparagus'' native to Eurasia. Widely cultivated as a vegetable crop, its young shoots are used as a spring vegetable. Description Asparagus is an herbaceous, perennial plant growing typically to tall, with stout stems with much-branched, feathery foliage. It has been known to grow as long as . The 'leaves' are needle-like cladodes (Aerial stem modification, modified stems) in the Leaf#Morphology, axils of scale leaves; they are long and broad, and clustered in fours, up to 15, together, in a rose-like shape. The root system, often referred to as a 'crown', is adventitious; the root type is Fascicle (botany), fasciculated. The flowers are bell-shaped, greenish-white to yellowish, long, with six tepals partially fused together at the base; they are produced singly or in clusters of two or three in the junctions of the branchlets. It is usually dioecious, with male ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
