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Plasmalogens
Glycerophospholipids of biochemical relevance are divided into three subclasses based on the substitution present at the sn-1 position of the glycerol backbone: acyl, alkyl and alkenyl. Of these, the alkyl and alkenyl moiety in each case form an ether bond, which makes for two types of ether phospholipids, plasmanyl (alkyl moiety at sn-1), and plasmenyl (alkenyl moiety with vinyl ether linkage at sn-1). Plasmalogens are plasmenyls with an ester (acyl group) linked lipid at the sn-2 position of the glycerol backbone, chemically designated 1-0(1Z-alkenyl)-2-acyl-glycerophospholipids. The lipid attached to the vinyl ether at sn-1 can be C16:0, C18:0, or C18:1 (saturated and monounsaturated), and the lipid attached to the acyl group at sn-2 can be C22:6 ω-3 (docosahexaenoic acid) or C20:4 ω-6 (arachidonic acid), (both are polyunsaturated acids). Plasmalogens are classified according to their head group, mainly as PC plasmalogens (plasmenylcholines) and PE plasmalogens (plasmenyleth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peroxisome
A peroxisome () is a membrane-bound organelle, a type of microbody, found in the cytoplasm of virtually all eukaryotic cells. Peroxisomes are oxidative organelles. Frequently, molecular oxygen serves as a co-substrate, from which hydrogen peroxide (H2O2) is then formed. Peroxisomes owe their name to hydrogen peroxide generating and scavenging activities. They perform key roles in lipid metabolism and the conversion of reactive oxygen species. Peroxisomes are involved in the catabolism of very long chain fatty acids, branched chain fatty acids, bile acid intermediates (in the liver), D-amino acids, and polyamines, the reduction of reactive oxygen species – specifically hydrogen peroxide – and the biosynthesis of plasmalogens, i.e., ether phospholipids critical for the normal function of mammalian brains and lungs. They also contain approximately 10% of the total activity of two enzymes ( Glucose-6-phosphate dehydrogenase and 6-Phosphogluconate dehydrogenase) in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhizomelic Chondrodysplasia Punctata
Rhizomelic chondrodysplasia punctata is a rare developmental brain disorder characterized by systemic shortening of the proximal bones (i.e. rhizomelia), seizures, recurrent respiratory tract infections and congenital cataracts. The affected individuals have low levels of plasmalogens. Signs and symptoms Rhizomelic chondrodysplasia punctata has the following symptoms: * Bilateral shortening of the femur * Post-natal growth problems (deficiency) * Cataracts * Intellectual disability * Possible seizures * Possible infections of respiratory tract Genetics This condition is a consequence of mutations in the PEX7 gene, the GNPAT gene (which is located on chromosome 1) or the AGPS gene. The condition is acquired in an autosomal recessive manner. Pathophysiology The mechanism of rhizomelic chondrodysplasia punctata in the case of ''type 1'' of this condition one finds that peroxisome objective is PEX7, in peroxisome assembly. There are 3 pathways that ''count on'' PEX7 an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peroxisome Biogenesis Disorders
Peroxisomal disorders represent a class of medical conditions caused by defects in peroxisome functions. This may be due to defects in single enzymes important for peroxisome function or in peroxins, proteins encoded by ''PEX'' genes that are critical for normal peroxisome assembly and biogenesis. Peroxisome biogenesis disorders Peroxisome biogenesis disorders (PBDs) include the Zellweger syndrome spectrum (PBD-ZSD) and rhizomelic chondrodysplasia punctata type 1 (RCDP1). PBD-ZSD represents a continuum of disorders including infantile Refsum disease, neonatal adrenoleukodystrophy, and Zellweger syndrome. Collectively, PBDs are autosomal recessive developmental brain disorders that also result in skeletal and craniofacial dysmorphism, liver dysfunction, progressive sensorineural hearing loss, and retinopathy. PBD-ZSD is most commonly caused by mutations in the ''PEX1'', ''PEX6'', ''PEX10'', ''PEX12'', and ''PEX26'' genes. This results in the over-accumulation of very long chain f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zellweger Syndrome
Zellweger syndrome is a rare congenital disorder characterized by the reduction or absence of functional peroxisomes in the cells of an individual. It is one of a family of disorders called Zellweger spectrum disorders which are leukodystrophies. Zellweger syndrome is named after Hans Zellweger (1909–1990), a Swiss-American pediatrician, a professor of pediatrics and genetics at the University of Iowa who researched this disorder. Signs and symptoms Zellweger syndrome is one of three peroxisome biogenesis disorders which belong to the Zellweger spectrum of peroxisome biogenesis disorders (PBD-ZSD). The other two disorders are neonatal adrenoleukodystrophy (NALD), and infantile Refsum disease (IRD). Although all have a similar molecular basis for disease, Zellweger syndrome is the most severe of these three disorders. Zellweger syndrome is associated with impaired neuronal migration, neuronal positioning, and brain development. In addition, individuals with Zellweger syndrome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fibroblast
A fibroblast is a type of biological cell that synthesizes the extracellular matrix and collagen, produces the structural framework ( stroma) for animal tissues, and plays a critical role in wound healing. Fibroblasts are the most common cells of connective tissue in animals. Structure Fibroblasts have a branched cytoplasm surrounding an elliptical, speckled nucleus having two or more nucleoli. Active fibroblasts can be recognized by their abundant rough endoplasmic reticulum. Inactive fibroblasts (called fibrocytes) are smaller, spindle-shaped, and have a reduced amount of rough endoplasmic reticulum. Although disjointed and scattered when they have to cover a large space, fibroblasts, when crowded, often locally align in parallel clusters. Unlike the epithelial cells lining the body structures, fibroblasts do not form flat monolayers and are not restricted by a polarizing attachment to a basal lamina on one side, although they may contribute to basal lamina components in so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethanolamine
Ethanolamine (2-aminoethanol, monoethanolamine, ETA, or MEA) is an organic chemical compound with the formula or . The molecule is bifunctional, containing both a primary amine and a primary alcohol. Ethanolamine is a colorless, viscous liquid with an odor reminiscent of ammonia.. ETA molecules are a component in the formation of cellular membranes and are thus a molecular building block for life. It was thought to exist only on Earth and on certain asteroids, but in 2021 evidence was found that ETA molecules exist in interstellar space. Derivatives of ethanolamine are widespread in nature; e.g., lipids, as precursor of a variety of ''N''-acylethanolamines (NAEs), that modulate several animal and plant physiological processes such as seed germination, plant–pathogen interactions, chloroplast development and flowering, as well as precursor, combined with arachidonic acid 20: 4, ω-6), to form the endocannabinoid anandamide (AEA: ; 20:4, ω-6). The ethanolamines comprise ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrolysis
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions in which water is the nucleophile. Biological hydrolysis is the cleavage of biomolecules where a water molecule is consumed to effect the separation of a larger molecule into component parts. When a carbohydrate is broken into its component sugar molecules by hydrolysis (e.g., sucrose being broken down into glucose and fructose), this is recognized as saccharification. Hydrolysis reactions can be the reverse of a condensation reaction in which two molecules join into a larger one and eject a water molecule. Thus hydrolysis adds water to break down, whereas condensation builds up by removing water. Types Usually hydrolysis is a chemical process in which a molecule of water is added to a substance. Sometimes this addition causes both the substance and water molecule to split into two parts. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1-alkenyl-2-acylglycerol Choline Phosphotransferase
In enzymology, a 1-alkenyl-2-acylglycerol choline phosphotransferase () is an enzyme that catalyzes the chemical reaction :CDP-choline + 1-alkenyl-2-acylglycerol \rightleftharpoons CMP + plasmenylcholine Thus, the two substrates of this enzyme are CDP-choline and 1-alkenyl-2-acylglycerol, whereas its two products are CMP and plasmenylcholine. This enzyme belongs to the family of transferases, specifically those transferring non-standard substituted phosphate groups. The systematic name of this enzyme class is CDP-choline:1-alkenyl-2-acylglycerol cholinephosphotransferase. This enzyme is also called CDP-choline-1-alkenyl-2-acyl-glycerol phosphocholinetransferase. This enzyme participates in ether lipid metabolism In organic chemistry, ethers are a class of compounds that contain an ether group—an oxygen atom connected to two alkyl or aryl groups. They have the general formula , where R and R′ represent the alkyl or aryl groups. Ethers can again be .... References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphotransferase
Phosphotransferases are a category of enzymes ( EC number 2.7) that catalyze phosphorylation reactions. The general form of the reactions they catalyze is: :A-P + B \rightleftharpoons B-P + A Where ''P'' is a phosphate group and A and B are the donating and accepting molecules, respectively. Classification Phosphotransferases are generally classified according to the acceptor molecule. , Classification in this article follows the rules of Enzyme Nomenclature of the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (NC-IUBMB). *EC 2.7.1 Phosphotransferases with an alcohol group as acceptor *EC 2.7.2 Phosphotransferases with a |
Phosphatidic Acid
Phosphatidic acids are anionic phospholipids important to cell signaling and direct activation of lipid-gated ion channels. Hydrolysis of phosphatidic acid gives rise to one molecule each of glycerol and phosphoric acid and two molecules of fatty acids. They constitute about 0.25% of phospholipids in the bilayer. Structure Phosphatidic acid consists of a glycerol backbone, with, in general, a saturated fatty acid bonded to carbon-1, an unsaturated fatty acid bonded to carbon-2, and a phosphate group bonded to carbon-3. Formation and degradation Besides de novo synthesis, PA can be formed in three ways: * By phospholipase D (PLD), via the hydrolysis of the P-O bond of phosphatidylcholine (PC) to produce PA and choline. * By the phosphorylation of diacylglycerol (DAG) by DAG kinase (DAGK). * By the acylation of lysophosphatidic acid by lysoPA-acyltransferase (LPAAT); this is the most common pathway.Devlin, T. M. 2004. ''Bioquímica'', 4ª edición. Reverté, Barcelona. The glycer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acyltransferase
Acyltransferase is a type of transferase enzyme that acts upon acyl groups. Examples include: * Glyceronephosphate O-acyltransferase * Lecithin-cholesterol acyltransferase *Long-chain-alcohol O-fatty-acyltransferase In enzymology, a long-chain-alcohol O-fatty-acyltransferase () is an enzyme that catalyzes the chemical reaction :acyl-CoA + a long-chain alcohol \rightleftharpoons CoA + a long-chain ester Thus, the two substrates of this enzyme are acyl-Co ... See also * Acetyltransferase External links * Transferases EC 2.3 {{2.3-enzyme-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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