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Hydroxysteroid Sulfotransferase
Bile salt sulfotransferase also known as hydroxysteroid sulfotransferase (HST) or sulfotransferase 2A1 (ST2A1) is an enzyme that in humans is encoded by the ''SULT2A1'' gene. Function Sulfotransferase enzymes catalyze the sulfate conjugation of many hormones, neurotransmitters, drugs, and xenobiotic compounds. These cytosolic enzymes are different in their tissue distributions and substrate specificities. The gene structure (number and length of exons) is similar among family members. This gene is primarily expressed in liver and adrenal tissues where the encoded protein sulfonates steroids and bile acids. See also * Steroid sulfotransferase * Steroidogenic enzyme __NOTOC__ Steroidogenic enzymes are enzymes that are involved in steroidogenesis and steroid biosynthesis. They are responsible for the biosynthesis of the steroid hormones, including sex steroids (androgens, estrogens, and progestogens) and cortic ... References Further reading * * * * * * * * * * * * * * * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the 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 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 are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfotransferase
Sulfotransferases (SULTs) are transferase enzymes that catalyze the transfer of a sulfo group from a donor molecule to an acceptor alcohol or amine. The most common sulfo group donor is 3'-phosphoadenosine-5'-phosphosulfate (PAPS). In the case of alcohol as acceptor, the product is a sulfate (R-OSO3−), whereas an amine leads to a sulfamate (R-NH-SO3−). Both reactive groups for a sulfonation via sulfotransferases may be part of a protein, lipid, carbohydrate or steroid. Examples The following are examples of sulfotransferases: * carbohydrate sulfotransferase: CHST1, CHST2, CHST3, CHST4, CHST5, CHST6, CHST7, CHST8, CHST9, CHST10, CHST11, CHST12, CHST13, CHST14 * galactose-3-O-sulfotransferase: GAL3ST1, GAL3ST2, GAL3ST3, GAL3ST4 * heparan sulfate 2-O-sulfotransferase: HS2ST1 * heparan sulfate 3-O-sulfotransferase: HS3ST1, HS3ST2, HS3ST3A1, HS3ST3B1, HS3ST4, HS3ST5, HS3ST6 * heparan sulfate 6-O-sulfotransferase: HS6ST1, HS6ST2, HS6ST3 * N-deacetylase ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfation
Sulfation is the chemical reaction that entails the addition of SO3 group. In principle, many sulfations would involve reactions of sulfur trioxide (SO3). In practice, most sulfations are effected less directly. Regardless of the mechanism, the installation of a sulfate-like group on a substrate leads to substantial changes. Sulfation in industry Sulfation of calcium oxides Sulfation is a process used to remove "sulfur" from the combustion of fossil fuels. The goal is to minimize the pollution by the combusted gases. Combustion of sulfur-containing fuels releases sulfur dioxide, which, in the atmosphere, oxidizes to the equivalent of sulfuric acid, which is corrosive. To minimize the problem, the combustion is often conducted in the presence of calcium oxide or calcium carbonate, which, directly or indirectly, bind sulfur dioxide and some oxygen to give calcium sulfate. The net reaction is: :CaO + SO2 → CaSO3 :CaSO3 + 1/2 O2 → CaSO4 or the net reaction is sulfa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steroid Sulfotransferase
In enzymology, a steroid sulfotransferase () is an enzyme that catalyzes the chemical reaction :3'-phosphoadenylyl sulfate + a phenolic steroid \rightleftharpoons adenosine 3',5'-bisphosphate + steroid O-sulfate Thus, the two substrates of this enzyme are 3'-phosphoadenylyl sulfate and phenolic steroid, whereas its two products are adenosine 3',5'-bisphosphate and steroid O-sulfate. This enzyme belongs to the family of transferases, specifically the sulfotransferases, which transfer sulfur-containing groups. The systematic name of this enzyme class is 3'-phosphoadenylyl-sulfate:phenolic-steroid sulfotransferase. This enzyme is also called steroid alcohol sulfotransferase. This enzyme participates in steroid metabolism. Genes Of 62 sulfotransferase genes in the human genome, 16 represent cytoplasmic sulfotransferases, and of these 16 cytoplasmic sulfotransferases, five have been found to act as steroid sulfotransferases. These five sulfotransferase genes are SULT1A1, SU ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steroidogenic Enzyme
__NOTOC__ Steroidogenic enzymes are enzymes that are involved in steroidogenesis and steroid biosynthesis. They are responsible for the biosynthesis of the steroid hormones, including sex steroids (androgens, estrogens, and progestogens) and corticosteroids (glucocorticoids and mineralocorticoids), as well as neurosteroids, from cholesterol. Steroidogenic enzymes are most highly expressed in classical steroidogenic tissues, such as the testis, ovary, and adrenal cortex, but are also present in other tissues in the body. List of steroidogenic enzymes * Steroid desmolases ** Cholesterol side-chain cleavage enzyme (20,22-desmolase) – steroid synthesis ** 17,20-Lyase (17,20-desmolase) – androgen synthesis * Steroid hydroxylases ** 11β-Hydroxylase – corticosteroid synthesis ** 17α-Hydroxylase – androgen and glucocorticoid synthesis ** 18-Hydroxylase (aldosterone synthase) – mineralocorticoid synthesis ** 21-Hydroxylase – corticosteroid synthesis ** Cytochrome P450 ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
