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Transaldolase Deficiency
Transaldolase deficiency is a disease characterised by abnormally low levels of the transaldolase enzyme. It is a metabolic enzyme involved in the pentose phosphate pathway. It is caused by mutation in the transaldolase gene (TALDO1). It was first described by Verhoeven et al. in 2001. Signs and Symptoms The leading symptoms of Transaldolase Deficiency are coagulopathy, thrombocytopenia, hepatosplenomegaly, hepatic fibrosis and dysmorphic features. The dysmorphic features can include antimongoloid slant, low-set ears, and cutis laxa. Those affected by this disease have abnormal polyol concentrations in urine and other bodily fluids, this can determined by an abnormal liver function tests. With transaldolase deficiency there is a buildup of sedoheptulose 7-phosphate (it is increased six to sevenfold in the blood compared to normal), which decreases the change of ribose 5-phosphate into glucose 6-phosphate. This reaction is important in releasing NADPH. Reduced glutathione i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transaldolase
Transaldolase is an enzyme () of the non-oxidative phase of the pentose phosphate pathway. In humans, transaldolase is encoded by the ''TALDO1'' gene. The following chemical reaction is catalyzed by transaldolase: : sedoheptulose 7-phosphate + glyceraldehyde 3-phosphate \rightleftharpoons erythrose 4-phosphate + fructose 6-phosphate Clinical significance The pentose phosphate pathway has two metabolic functions: (1) generation of nicotinamide adenine dinucleotide phosphate (reduced NADPH), for reductive biosynthesis, and (2) formation of ribose, which is an essential component of ATP, DNA, and RNA. Transaldolase links the pentose phosphate pathway to glycolysis. In patients with deficiency of transaldolase, there's an accumulation of erythritol (from erythrose 4-phosphate), D-arabitol, and ribitol. The deletion in 3 base pairs in the ''TALDO1'' gene results in the absence of serine at position 171 of the transaldolase protein, which is part of a highly conserved region, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liver Cirrhosis
Cirrhosis, also known as liver cirrhosis or hepatic cirrhosis, and end-stage liver disease, is the impaired liver function caused by the formation of scar tissue known as fibrosis due to damage caused by liver disease. Damage causes tissue repair and subsequent formation of scar tissue, which over time can replace normal functioning tissue, leading to the impaired liver function of cirrhosis. The disease typically develops slowly over months or years. Early symptoms may include tiredness, weakness, loss of appetite, unexplained weight loss, nausea and vomiting, and discomfort in the right upper quadrant of the abdomen. As the disease worsens, symptoms may include itchiness, swelling in the lower legs, fluid build-up in the abdomen, jaundice, bruising easily, and the development of spider-like blood vessels in the skin. The fluid build-up in the abdomen may become spontaneously infected. More serious complications include hepatic encephalopathy, bleeding from dilated v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentose Phosphate Pathway
The pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt and the HMP Shunt) is a metabolic pathway parallel to glycolysis. It generates NADPH and pentoses (5-carbon sugars) as well as ribose 5-phosphate, a precursor for the synthesis of nucleotides. While the pentose phosphate pathway does involve oxidation of glucose, its primary role is anabolic rather than catabolic. The pathway is especially important in red blood cells (erythrocytes). There are two distinct phases in the pathway. The first is the oxidative phase, in which NADPH is generated, and the second is the non-oxidative synthesis of 5-carbon sugars. For most organisms, the pentose phosphate pathway takes place in the cytosol; in plants, most steps take place in plastids. Like glycolysis, the pentose phosphate pathway appears to have a very ancient evolutionary origin. The reactions of this pathway are mostly enzyme-catalyzed in modern cells, however, they also occ ... [...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 (substrates) into others ( 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 now often referred to as congenital metabolic diseases or inherited metabolic disorders. To this concept it's possible to include the new term of Enzymopathy. This term was created following the study of Biodynamic Enzymology, a science based on the study of the enzymes and their derivated products. Finally, ''inborn errors of metabolism'' were studied for the first time by British physician Archibald Garrod (1857–1936), in 1908. He is known for work that prefigured the "one g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transaldolase
Transaldolase is an enzyme () of the non-oxidative phase of the pentose phosphate pathway. In humans, transaldolase is encoded by the ''TALDO1'' gene. The following chemical reaction is catalyzed by transaldolase: : sedoheptulose 7-phosphate + glyceraldehyde 3-phosphate \rightleftharpoons erythrose 4-phosphate + fructose 6-phosphate Clinical significance The pentose phosphate pathway has two metabolic functions: (1) generation of nicotinamide adenine dinucleotide phosphate (reduced NADPH), for reductive biosynthesis, and (2) formation of ribose, which is an essential component of ATP, DNA, and RNA. Transaldolase links the pentose phosphate pathway to glycolysis. In patients with deficiency of transaldolase, there's an accumulation of erythritol (from erythrose 4-phosphate), D-arabitol, and ribitol. The deletion in 3 base pairs in the ''TALDO1'' gene results in the absence of serine at position 171 of the transaldolase protein, which is part of a highly conserved region, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyols
In organic chemistry, a polyol is an organic compound containing multiple hydroxyl groups (). The term "polyol" can have slightly different meanings depending on whether it is used in food science or polymer chemistry. Polyols containing two, three and four hydroxyl groups are diols, triols, and tetrols, respectively. Classification Polyols may be classified according to their chemistry. Some of these chemistries are polyether, polyester, polycarbonate and also acrylic polyols. Polyether polyols may be further subdivided and classified as polyethylene oxide or polyethylene glycol (PEG), polypropylene glycol (PPG) and Polytetrahydrofuran or PTMEG. These have 2, 3 and 4 carbons respectively per oxygen atom in the repeat unit. Polycaprolactone polyols are also commercially available. There is also an increasing trend to use biobased (and hence renewable) polyols. Uses Polyether polyols have numerous uses. As an example, polyurethane foam is a big user of polyether polyols. Polyes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
D-erythrose 4-phosphate
Erythrose 4-phosphate is a phosphate of the simple sugar erythrose. It is an intermediate in the pentose phosphate pathway and the Calvin cycle. In addition, it serves as a precursor in the biosynthesis of the aromatic amino acids tyrosine, phenylalanine, and tryptophan. It is used in the first step of the shikimate pathway. At this stage, phosphoenolpyruvate and erythrose-4-phosphate react to form 3-deoxy-D-arabinoheptulosonate-7-phosphate (DAHP), in a reaction catalyzed by the enzyme DAHP synthase. : It also used in 3-hydroxy-1-aminoacetone phosphate biosynthesis, which is a precursor of vitamin B6 in DXP-dependent pathway. Erythrose-4-phosphate dehydrogenase In enzymology, an erythrose-4-phosphate dehydrogenase () is an enzyme that catalyzes the chemical reaction :D-erythrose 4-phosphate + NAD+ + H2O \rightleftharpoons 4-phosphoerythronate + NADH + 2 H+ The 3 substrates of this enzyme are D-eryt ... is used to produce erythronate-4-phosphate. References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fructose 6-phosphate
Fructose 6-phosphate (sometimes called the Neuberg ester) is a derivative of fructose, which has been phosphorylated at the 6-hydroxy group. It is one of several possible fructosephosphates. The β-D-form of this compound is very common in cells. The great majority of glucose is converted to fructose 6-phosphate upon entering a cell. Fructose is predominantly converted to fructose 1-phosphate by fructokinase following cellular import. History The name ''Neuberg ester'' comes from the German biochemist Carl Neuberg. In 1918, he found that the compound (later identified as fructose 6-phosphate) was beproduced by mild acid hydrolysis of fructose 2,6-bisphosphate.Fruton, Joseph S. ''Proteins, Enzymes, Genes: The Interplay of Chemistry and Biology''. Yale University Press: New Haven, 1999. p 292 In glycolysis Fructose 6-phosphate lies within the glycolysis metabolic pathway and is produced by isomerisation of glucose 6-phosphate. It is in turn further phosphorylated to fructo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
D-glyceraldehyde 3-phosphate
Glyceraldehyde 3-phosphate, also known as triose phosphate or 3-phosphoglyceraldehyde and abbreviated as G3P, GA3P, GADP, GAP, TP, GALP or PGAL, is a metabolite that occurs as an intermediate in several central pathways of all organisms.Nelson, D. L.; Cox, M. M. "Lehninger, Principles of Biochemistry" 3rd Ed. Worth Publishing: New York, 2000. . With the chemical formula H(O)CCH(OH)CH2OPO32-, this anion is a monophosphate ester of glyceraldehyde. An intermediate in both glycolysis and gluconeogenesis Formation D-glyceraldehyde 3-phosphate is formed from the following three compounds in reversible reactions: *Fructose-1,6-bisphosphate (F1,6BP), catalyzed by aldolase. ''The numbering of the carbon atoms indicates the fate of the carbons according to their position in fructose 6-phosphate.'' *Dihydroxyacetone phosphate (DHAP), catalyzed by triose phosphate isomerase. *1,3-bisphosphoglycerate (1,3BPG), catalyzed by glyceraldehyde 3-phosphate dehydrogenase. As a substr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transaldolase Annotated PENTOSE PHOSPHATE Pathway
Transaldolase is an enzyme () of the non-oxidative phase of the pentose phosphate pathway. In humans, transaldolase is encoded by the ''TALDO1'' gene. The following chemical reaction is catalyzed by transaldolase: : sedoheptulose 7-phosphate + glyceraldehyde 3-phosphate \rightleftharpoons erythrose 4-phosphate + fructose 6-phosphate Clinical significance The pentose phosphate pathway has two metabolic functions: (1) generation of nicotinamide adenine dinucleotide phosphate (reduced NADPH), for reductive biosynthesis, and (2) formation of ribose, which is an essential component of ATP, DNA, and RNA. Transaldolase links the pentose phosphate pathway to glycolysis. In patients with deficiency of transaldolase, there's an accumulation of erythritol (from erythrose 4-phosphate), D- arabitol, and ribitol. The deletion in 3 base pairs in the ''TALDO1'' gene results in the absence of serine at position 171 of the transaldolase protein, which is part of a highly conserve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spermatozoa
A spermatozoon (; also spelled spermatozoön; ; ) is a motile sperm cell (biology), cell, or moving form of the ploidy, haploid cell (biology), cell that is the male gamete. A spermatozoon Fertilization, joins an ovum to form a zygote. (A zygote is a single cell, with a complete set of chromosomes, that normally develops into an embryo.) Sperm cells contribute approximately half of the nuclear gene, genetic information to the diploid offspring (excluding, in most cases, mitochondrial DNA). In mammals, the sex of the offspring is determined by the sperm cell: a spermatozoon bearing an X chromosome will lead to a female (XX) offspring, while one bearing a Y chromosome will lead to a male (XY) offspring. Sperm cells were first observed in Antonie van Leeuwenhoek's laboratory in 1677. Mammalian spermatozoon structure, function, and size Humans The human sperm cell is the Gamete, reproductive cell in males and will only survive in warm environments; once it leaves the male body th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentose Phosphate Pathway
The pentose phosphate pathway (also called the phosphogluconate pathway and the hexose monophosphate shunt and the HMP Shunt) is a metabolic pathway parallel to glycolysis. It generates NADPH and pentoses (5-carbon sugars) as well as ribose 5-phosphate, a precursor for the synthesis of nucleotides. While the pentose phosphate pathway does involve oxidation of glucose, its primary role is anabolic rather than catabolic. The pathway is especially important in red blood cells (erythrocytes). There are two distinct phases in the pathway. The first is the oxidative phase, in which NADPH is generated, and the second is the non-oxidative synthesis of 5-carbon sugars. For most organisms, the pentose phosphate pathway takes place in the cytosol; in plants, most steps take place in plastids. Like glycolysis, the pentose phosphate pathway appears to have a very ancient evolutionary origin. The reactions of this pathway are mostly enzyme-catalyzed in modern cells, however, they also occ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
