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Methylcrotonyl-CoA Carboxylase
Methylcrotonyl CoA carboxylase (, MCC) (3-methylcrotonyl CoA carboxylase, methylcrotonoyl-CoA carboxylase) is a biotin-requiring enzyme located in the mitochondria. MCC uses bicarbonate as a carboxyl group source to catalyze the carboxylation of a carbon adjacent to a carbonyl group performing the fourth step in processing leucine, an essential amino acid. Structure Gene Human MCC is a biotin dependent mitochondrial enzyme formed by the two subunits MCCCα and MCCCβ, encoded by ''MCCC1'' and ''MCCC2'' respectively. MCCC1 gene has 21 exons and resides on chromosome 3 at q27. MCCC2 gene has 19 exons and resides on chromosome 5 at q12-q13. Protein The enzyme contains α and β subunits. Human MCCCα is composed of 725 amino acids which harbor a covalently bound biotin essential for the ATP-dependent carboxylation; MCCCβ has 563 amino acids that possess carboxyltransferase activity which presumably is essential for binding to 3-methylcrotonyl CoA. The MCC holoenzyme is thought ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biotin
Biotin (also known as vitamin B7 or vitamin H) is one of the B vitamins. It is involved in a wide range of metabolic processes, both in humans and in other organisms, primarily related to the utilization of fats, carbohydrates, and amino acids. The name ''biotin'', borrowed from the German , derives from the Ancient Greek word (; 'life') and the suffix "-in" (a suffix used in chemistry usually to indicate 'forming'). Biotin appears as a white, needle-like crystalline solid. Chemical description Biotin is classified as a heterocyclic compound, with a sulfur-containing tetrahydrothiophene ring fused to a ureido group. A C5-carboxylic acid side chain is appended to the former ring. The ureido ring, containing the −N−CO−N− group, serves as the carbon dioxide carrier in carboxylation reactions. Biotin is a coenzyme for five carboxylase enzymes, which are involved in the catabolism of amino acids and fatty acids, synthesis of fatty acids, and gluconeogenesis. Biotinylat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3-methylglutaconyl CoA
3-Methylglutaconyl-CoA (MG-CoA), also known as β-methylglutaconyl-CoA, is an intermediate in the metabolism of leucine. It is metabolized into HMG-CoA. Leucine metabolism See also * Methylcrotonyl-CoA carboxylase * Methylglutaconyl-CoA hydratase 3-Methylglutaconyl-CoA hydratase, also known as MG-CoA hydratase and AUH, is an enzyme () encoded by the ''AUH'' gene on chromosome 19. It is a member of the enoyl-CoA hydratase/isomerase superfamily, but it is the only member of that family that ... References Organophosphates Thioesters of coenzyme A {{biochem-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acidosis
Acidosis is a biological process producing hydrogen ions and increasing their concentration in blood or body fluids. pH is the negative log of hydrogen ion concentration and so it is decreased by a process of acidosis. Acidemia The term acidemia describes the state of low blood pH, when arterial pH falls below 7.35 (except in the fetus – see below) while ''acidosis'' is used to describe the processes leading to these states. The use of acidosis for a low pH creates an ambiguity in its meaning. The difference is important where a patient has factors causing both acidosis and alkalosis, wherein the relative severity of both determines whether the result is a high, low, or normal pH. Alkalemia occurs at a pH over 7.45. Arterial blood gas analysis and other tests are required to separate the main causes. In certain situations the main cause is clear. For instance, a diabetic with ketoacidosis is a recognizable case where the main cause of acidemia is essentially obvious. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SIRT4
Sirtuin 4, also known as SIRT4, is a mitochondria, mitochondrial protein which in humans is encoded by the ''SIRT4'' gene. SIRT4 is member of the mammalian sirtuin family of proteins, which are Homology (biology)#Homology of sequences in genetics, homologs to the yeast Sir2 protein. SIRT4 exhibits NAD+-dependent protein deacetylase, deacetylase activity. Function SIRT4 is a mitochondrial ADP-ribosyltransferase that inhibits mitochondrial glutamate dehydrogenase 1 activity, thereby downregulating insulin secretion in response to amino acids. A deacetylation of malonyl-CoA decarboxylase enzyme by SIRT4 represses the enzyme activity, inhibiting Beta oxidation, fatty acid oxidation in muscle and liver cells. SIRT4 has a suppressive effect on peroxisome proliferator-activated receptor alpha (PPAR-α) which Downregulation and upregulation, downregulates fatty acid oxidation in liver cells. Acetylation, Deacetylation of ADP/ATP translocase 2 (ANT2) increases cellular ATP by dampening Un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Negative Feedback
Negative feedback (or balancing feedback) occurs when some function (Mathematics), function of the output of a system, process, or mechanism is feedback, fed back in a manner that tends to reduce the fluctuations in the output, whether caused by changes in the input or by other disturbances. Whereas positive feedback tends to instability via exponential growth, oscillation or chaos theory, chaotic behavior, negative feedback generally promotes stability. Negative feedback tends to promote a settling to List of types of equilibrium, equilibrium, and reduces the effects of perturbations. Negative feedback loops in which just the right amount of correction is applied with optimum timing, can be very stable, accurate, and responsive. Negative feedback is widely used in Mechanical engineering, mechanical and electronic engineering, and it is observed in many other fields including biology, chemistry and economics. General negative feedback systems are studied in Control engin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleophilic Attack
In chemistry, a nucleophile is a chemical species that forms bonds by donating an electron pair. All molecules and ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they are Lewis bases. ''Nucleophilic'' describes the affinity of a nucleophile to bond with positively charged atomic nuclei. Nucleophilicity, sometimes referred to as nucleophile strength, refers to a substance's nucleophilic character and is often used to compare the affinity of atoms. Neutral nucleophilic reactions with solvents such as alcohols and water are named solvolysis. Nucleophiles may take part in nucleophilic substitution, whereby a nucleophile becomes attracted to a full or partial positive charge, and nucleophilic addition. Nucleophilicity is closely related to basicity. The difference between the two is, that basicity is a thermodynamic property (i.e. relates to an equilibrium state), but nucleophilicity is a kinetic property ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenosine Triphosphate
Adenosine triphosphate (ATP) is a nucleoside triphosphate that provides energy to drive and support many processes in living cell (biology), cells, such as muscle contraction, nerve impulse propagation, and chemical synthesis. Found in all known forms of life, it is often referred to as the "molecular unit of currency" for intracellular energy transfer. When consumed in a Metabolism, metabolic process, ATP converts either to adenosine diphosphate (ADP) or to adenosine monophosphate (AMP). Other processes regenerate ATP. It is also a Precursor (chemistry), precursor to DNA and RNA, and is used as a coenzyme. An average adult human processes around 50 kilograms (about 100 mole (unit), moles) daily. From the perspective of biochemistry, ATP is classified as a nucleoside triphosphate, which indicates that it consists of three components: a nitrogenous base (adenine), the sugar ribose, and the Polyphosphate, triphosphate. Structure ATP consists of three parts: a sugar, an amine base ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carnitine
Carnitine is a quaternary ammonium compound involved in metabolism in most mammals, plants, and some bacteria. In support of energy metabolism, carnitine transports long-chain fatty acids from the cytosol into mitochondria to be oxidized for free energy production, and also participates in removing products of metabolism from cells. Given its key metabolic roles, carnitine is concentrated in tissues like skeletal and cardiac muscle that metabolize fatty acids as an energy source. Generally individuals, including strict vegetarians, synthesize enough L-carnitine in vivo. Carnitine exists as one of two stereoisomers: the two enantiomers -carnitine (''S''-(+)-) and -carnitine (''R''-(−)-). Both are biologically active, but only -carnitine naturally occurs in animals, and -carnitine is toxic as it inhibits the activity of the -form. At room temperature, pure carnitine is a whiteish powder, and a water-soluble zwitterion with relatively low toxicity. Derived from amino acids, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metabolic Acidosis
Metabolic acidosis is a serious electrolyte disorder characterized by an imbalance in the body's acid-base balance. Metabolic acidosis has three main root causes: increased acid production, loss of bicarbonate, and a reduced ability of the kidneys to excrete excess acids. Metabolic acidosis can lead to acidemia, which is defined as arterial blood pH that is lower than 7.35. Acidemia and acidosis are not mutually exclusive – pH and hydrogen ion concentrations also depend on the coexistence of other acid-base disorders; therefore, pH levels in people with metabolic acidosis can range from low to high. Acute metabolic acidosis, lasting from minutes to several days, often occurs during serious illnesses or hospitalizations, and is generally caused when the body produces an excess amount of organic acids ( ketoacids in ketoacidosis, or lactic acid in lactic acidosis). A state of chronic metabolic acidosis, lasting several weeks to years, can be the result of impaired kidney fun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inborn Error Of Metabolism
Inborn errors of metabolism form a large class of genetic diseases involving congenital disorders of enzyme activities. The majority are due to defects of single genes that code for enzymes that facilitate conversion of various substances (substrate (biochemistry), substrates) into others (Product (chemistry), products). In most of the disorders, problems arise due to accumulation of substances which are toxic or interfere with normal function, or due to the effects of reduced ability to synthesize essential compounds. Inborn errors of metabolism are often referred to as congenital metabolic diseases or inherited metabolic disorders. Another term used to describe these disorders is "enzymopathies". This term was created following the study of Biochemical Processes, biodynamic enzymology, a science based on the study of the enzymes and their products. Finally, ''inborn errors of metabolism'' were studied for the first time by British physician Archibald Garrod (1857–1936), in 1908. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MCC Deficiency
3-Methylcrotonyl-CoA carboxylase deficiency also known as 3-Methylcrotonylglycinuria is an Inborn errors of metabolism, inborn error of leucine metabolism and is inherited through an autosomal recessive fashion. 3-Methylcrotonyl-CoA carboxylase deficiency is caused by mutations in the MCCC1 gene, formerly known as MMCA, or the MCCC2 gene, formerly known as MCCB. MCCC1 encodes the a-Subunit protein, subunits of 3-methylcrotonyl-CoA carboxylase while MCCC2 encodes the b-Subunit protein, subunits. The clinical presentation of 3-Methylcrotonyl-CoA carboxylase deficiency is varied, even within members of the same family. Manifestations of 3-Methylcrotonyl-CoA carboxylase deficiency range from asymptomatic to neonatal onset with extreme Neurological disorder, neurological symptoms and even fatal cases. 3-Methylcrotonyl-CoA carboxylase deficiency is diagnosed by increased 3-hydroxyisovaleric acid and 3-methylcrotonylglycine in the urine. 3-hydroxyisovalerylcarnitine is often found in bot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetyl CoA
Acetyl-CoA (acetyl coenzyme A) is a molecule that participates in many biochemical reactions in protein, carbohydrate and lipid metabolism. Its main function is to deliver the acetyl group to the citric acid cycle (Krebs cycle) to be oxidized for energy production. Coenzyme A (CoASH or CoA) consists of a β-mercaptoethylamine group linked to pantothenic acid (vitamin B5) through an amide linkage and 3'-phosphorylated ADP. The acetyl group (indicated in blue in the structural diagram on the right) of acetyl-CoA is linked to the sulfhydryl substituent of the β-mercaptoethylamine group. This thioester linkage is a "high energy" bond, which is particularly reactive. Hydrolysis of the thioester bond is exergonic (−31.5 kJ/mol). CoA is acetylated to acetyl-CoA by the breakdown of carbohydrates through glycolysis and by the breakdown of fatty acids through β-oxidation. Acetyl-CoA then enters the citric acid cycle, where the acetyl group is oxidized to carbon dioxide and wat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
