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SGOT
Aspartate transaminase (AST) or aspartate aminotransferase, also known as AspAT/ASAT/AAT or (serum) glutamic oxaloacetic transaminase (GOT, SGOT), is a pyridoxal phosphate (PLP)-dependent transaminase enzyme () that was first described by Arthur Karmen and colleagues in 1954. AST catalyzes the reversible transfer of an α-amino group between aspartate and glutamate and, as such, is an important enzyme in amino acid metabolism. AST is found in the liver, heart, skeletal muscle, kidneys, brain, red blood cells and gall bladder. Serum AST level, serum ALT (alanine transaminase) level, and their ratio (AST/ALT ratio) are commonly measured clinically as biomarkers for liver health. The tests are part of blood panels. The half-life of total AST in the circulation approximates 17 hours and, on average, 87 hours for ''mitochondrial'' AST. Aminotransferase is cleared by sinusoidal cells in the liver. Function Aspartate transaminase catalyzes the interconversion of aspartate and α- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transaminase
Transaminases or aminotransferases are enzymes that catalyze a transamination reaction between an amino acid and an α-keto acid. They are important in the synthesis of amino acids, which form proteins. Function and mechanism An amino acid contains an amine (NH2) group. A keto acid contains a keto (=O) group. In transamination, the NH2 group on one molecule is exchanged with the =O group on the other molecule. The amino acid becomes a keto acid, and the keto acid becomes an amino acid. Most transaminases are protein enzymes. However, some transamination activities of the ribosome have been found to be catalyzed by ribozymes (RNA enzymes). Examples being the hammerhead ribozyme, the VS ribozyme and the hairpin ribozyme. Transaminases require the coenzyme pyridoxal phosphate, which is converted into pyridoxamine in the first half-reaction, when an amino acid is converted into a keto acid. Enzyme-bound pyridoxamine in turn reacts with pyruvate, oxaloacetate, or alpha-ketoglut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aminotransferase
Transaminases or aminotransferases are enzymes that catalyze a transamination reaction between an amino acid and an α-keto acid. They are important in the synthesis of amino acids, which form proteins. Function and mechanism An amino acid contains an amine (NH2) group. A keto acid contains a keto (=O) group. In transamination, the NH2 group on one molecule is exchanged with the =O group on the other molecule. The amino acid becomes a keto acid, and the keto acid becomes an amino acid. Most transaminases are protein enzymes. However, some transamination activities of the ribosome have been found to be catalyzed by ribozymes (RNA enzymes). Examples being the hammerhead ribozyme, the VS ribozyme and the hairpin ribozyme. Transaminases require the coenzyme pyridoxal phosphate, which is converted into pyridoxamine in the first half-reaction, when an amino acid is converted into a keto acid. Enzyme-bound pyridoxamine in turn reacts with pyruvate, oxaloacetate, or alpha-ketogluta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyridoxal-phosphate
Pyridoxal phosphate (PLP, pyridoxal 5'-phosphate, P5P), the active form of vitamin B6, is a coenzyme in a variety of enzymatic reactions. The International Union of Biochemistry and Molecular Biology has catalogued more than 140 PLP-dependent activities, corresponding to ~4% of all classified activities. The versatility of PLP arises from its ability to covalently bind the substrate, and then to act as an electrophilic catalyst, thereby stabilizing different types of carbanionic reaction intermediates. Role as a coenzyme PLP acts as a coenzyme in all transamination reactions, and in certain decarboxylation, deamination, and racemization reactions of amino acids. The aldehyde group of PLP forms a Schiff-base linkage (internal aldimine) with the ε-amino group of a specific lysine group of the aminotransferase enzyme. The α-amino group of the amino acid substrate displaces the ε-amino group of the active-site lysine residue in a process known as transaldimination. The resulting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glutamate
Glutamic acid (symbol Glu or E; the ionic form is known as glutamate) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a non-essential nutrient for humans, meaning that the human body can synthesize enough for its use. It is also the most abundant excitatory neurotransmitter in the vertebrate nervous system. It serves as the precursor for the synthesis of the inhibitory gamma-aminobutyric acid (GABA) in GABA-ergic neurons. Its molecular formula is . Glutamic acid exists in three optically isomeric forms; the dextrorotatory -form is usually obtained by hydrolysis of gluten or from the waste waters of beet-sugar manufacture or by fermentation.Webster's Third New International Dictionary of the English Language Unabridged, Third Edition, 1971. Its molecular structure could be idealized as HOOC−CH()−()2−COOH, with two carboxyl groups −COOH and one amino group −. However, in the solid state and mildly acidic water solu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haloferax
In taxonomy, ''Haloferax'' (common abbreviation: ''Hfx.'') is a genus of the Haloferacaceae. Genetic exchange Cells of ''H. mediterranei'' and cells of the related species '' H. volcanii'' can undergo a process of genetic exchange between two cells which involves cell fusion resulting in a heterodiploid cell (containing two different chromosomes in one cell). Although this genetic exchange ordinarily occurs between two cells of the same species, it can also occur at a lower frequency between an ''H. mediterranei'' and an ''H. volcani'' cell. These two species have an average nucleotide sequence identity of 86.6%. During this exchange process, a diploid cell is formed that contains the full genetic repertoire of both parental cells, and genetic recombination is facilitated. Subsequently, the cells separate, giving rise to recombinant cells. Taxonomy As of 2022, 13 species are validly published under the genus ''Haloferax''. ;Proposed species Several species and novel binomial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitochondrion
A mitochondrion (; ) is an organelle found in the cells of most Eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is used throughout the cell as a source of chemical energy. They were discovered by Albert von Kölliker in 1857 in the voluntary muscles of insects. The term ''mitochondrion'' was coined by Carl Benda in 1898. The mitochondrion is popularly nicknamed the "powerhouse of the cell", a phrase coined by Philip Siekevitz in a 1957 article of the same name. Some cells in some multicellular organisms lack mitochondria (for example, mature mammalian red blood cells). A large number of unicellular organisms, such as microsporidia, parabasalids and diplomonads, have reduced or transformed their mitochondria into other structures. One eukaryote, ''Monocercomonoides'', is known to have completely lost its mitochondria, and one multicellular organism, '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GOT2
Aspartate aminotransferase, mitochondrial is an enzyme that in humans is encoded by the ''GOT2'' gene. Glutamic-oxaloacetic transaminase is a pyridoxal phosphate-dependent enzyme which exists in cytoplasmic and inner-membrane mitochondrial forms, GOT1 and GOT2, respectively. GOT plays a role in amino acid metabolism and the urea and Kreb's cycle. Also, GOT2 is a major participant in the malate-aspartate shuttle, which is a passage from the cytosol to the mitochondria. The two enzymes are homodimeric and show close homology. GOT2 has been seen to have a role in cell proliferation, especially in terms of tumor growth. Structure GOT2 is a dimer containing two identical subunits that hold overlapping subunit regions. The top and sides of the enzyme are made up of helices, while the bottom is formed by strands of beta sheets and extended hairpin loops. The subunit itself can be categorized into four different parts: a large domain, which binds pyridoxal-P, a small domain, an NH2-te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Blood Cell
Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "hollow vessel", with ''-cyte'' translated as "cell" in modern usage), are the most common type of blood cell and the vertebrate's principal means of delivering oxygen (O2) to the body tissues—via blood flow through the circulatory system. RBCs take up oxygen in the lungs, or in fish the gills, and release it into tissues while squeezing through the body's capillaries. The cytoplasm of a red blood cell is rich in hemoglobin, an iron-containing biomolecule that can bind oxygen and is responsible for the red color of the cells and the blood. Each human red blood cell contains approximately 270 million hemoglobin molecules. The cell membrane is composed of proteins and lipids, and this structure provides properties essential for physiolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytosol
The cytosol, also known as cytoplasmic matrix or groundplasm, is one of the liquids found inside cells (intracellular fluid (ICF)). It is separated into compartments by membranes. For example, the mitochondrial matrix separates the mitochondrion into many compartments. In the eukaryotic cell, the cytosol is surrounded by the cell membrane and is part of the cytoplasm, which also comprises the mitochondria, plastids, and other organelles (but not their internal fluids and structures); the cell nucleus is separate. The cytosol is thus a liquid matrix around the organelles. In prokaryotes, most of the chemical reactions of metabolism take place in the cytosol, while a few take place in membranes or in the periplasmic space. In eukaryotes, while many metabolic pathways still occur in the cytosol, others take place within organelles. The cytosol is a complex mixture of substances dissolved in water. Although water forms the large majority of the cytosol, its structure and prope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GOT1
Aspartate aminotransferase, cytoplasmic is an enzyme that in humans is encoded by the ''GOT1'' gene. Glutamic-oxaloacetic transaminase is a pyridoxal phosphate-dependent enzyme which exists in cytoplasmic and mitochondrial forms, GOT1 and GOT2, respectively. GOT plays a role in amino acid metabolism and the urea and tricarboxylic acid cycle The citric acid cycle (CAC)—also known as the Krebs cycle or the TCA cycle (tricarboxylic acid cycle)—is a series of chemical reactions to release stored energy through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins ...s. The two enzymes are homodimeric and show close homology. Interactive pathway map References Further reading * * * * * * * * * * * * * * * * {{gene-10-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Citric Acid Cycle
The citric acid cycle (CAC)—also known as the Krebs cycle or the TCA cycle (tricarboxylic acid cycle)—is a series of chemical reactions to release stored energy through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins. The Krebs cycle is used by organisms that respire (as opposed to organisms that ferment) to generate energy, either by anaerobic respiration or aerobic respiration. In addition, the cycle provides precursors of certain amino acids, as well as the reducing agent NADH, that are used in numerous other reactions. Its central importance to many biochemical pathways suggests that it was one of the earliest components of metabolism and may have originated abiogenically. Even though it is branded as a 'cycle', it is not necessary for metabolites to follow only one specific route; at least three alternative segments of the citric acid cycle have been recognized. The name of this metabolic pathway is derived from the citric acid (a tricarboxy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urea
Urea, also known as carbamide, is an organic compound with chemical formula . This amide has two amino groups (–) joined by a carbonyl functional group (–C(=O)–). It is thus the simplest amide of carbamic acid. Urea serves an important role in the metabolism of nitrogen-containing compounds by animals and is the main nitrogen-containing substance in the urine of mammals. It is a colorless, odorless solid, highly soluble in water, and practically non-toxic ( is 15 g/kg for rats). Dissolved in water, it is neither acidic nor alkaline. The body uses it in many processes, most notably nitrogen excretion. The liver forms it by combining two ammonia molecules () with a carbon dioxide () molecule in the urea cycle. Urea is widely used in fertilizers as a source of nitrogen (N) and is an important raw material for the chemical industry. In 1828 Friedrich Wöhler discovered that urea can be produced from inorganic starting materials, which was an important conceptual milestone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
