Nutrition Guide

In enzymology, a sphingomyelin synthase (EC 2.7.8.27) is an enzyme that catalyzes the chemical reaction a ceramide + a phosphatidylcholine a sphingomyelin + a 1,2-diacyl-sn-glycerol Thus, the two substrates of this enzyme are ceramide and phosphatidylcholine, whereas its two products are sphingomyelin and 1,2-diacyl-sn-glycerol. This enzyme belongs to the family of transferases, specifically those transferring non-standard substituted phosphate groups. The systematic name of this enzyme class is ceramide:phosphatidylcholine cholinephosphotransferase. Other names in common use include SM synthase, SMS1, and SMS2.

Hydrolysis of sphingomyelin is catalyzed by the enzyme sphingomyelinase. Because sphingomyelin is one of the four common phospholipids found in the plasma membrane of cells, the implications of this method of generating ceramide is that the cellular membrane is the target of extracellular signals leading to programmed cell death. There has been research suggesting that when ionizing radiation causes apoptosis in some cells, the radiation leads to the activation of sphingomyelinase in the cell membrane and ultimately, to ceramide generation

Sphingomyelin(SPH) is a type of sphingolipid found in animal cell membranes, especially in the membranous myelin sheath which surrounds some nerve cell axons. It usually consists of phosphorylcholine and ceramide. In humans SPH represents ~85% of all sphingolipids.

Sphingomyelinase phosphodiesterase or simply Sphingomyelinase (SMase) is a hydrolase enzyme that is involved in sphingolipid metabolism reactions. SMase is a member of the DNase I superfamily of enzymes and is responsible for breaking sphingomyelin (SM) down into phosphocholine and ceramide. The activation of SMase has been suggested as a major route for the production of ceramide in response to cellular stresses. [1]

Sphingosine is an amino alcohol that contains a long, unsaturated hydrocarbon chain. In sphingomyelin and glycolipids, the amino group of sphingosine is linked to FAs by an amide bond. In sphingomyelin the primary hydroxyl group of sphingosine is esterified to phosphoryl choline. In glycolipids, the sugar component is attached to this group. The simplest glycolipid is cerebroside, in which there is only one sugar residue, either Glc or Gal. More complex glycolipids, such as gangliosides, contain a branched chain of as many as seven sugar residues.

The following tables explain gating, gene, location and function of different types of calcium channels, both voltage and ligand-g

In enzymology, a ceramide cholinephosphotransferase (EC 2.7.8.3) is an enzyme that catalyzes the chemical reaction CDP-choline + N-acylsphingosine CMP + sphingomyelin Thus, the two substrates of this enzyme are CDP-choline and N-acylsphingosine, whereas its two products are CMP and sphingomyelin. 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:N-acylsphingosine cholinephosphotransferase. This enzyme is also called phosphorylcholine-ceramide transferase. This enzyme participates in sphingolipid metabolism.

Sphingomyelin can accumulate in a rare hereditary disease called Niemann-Pick Disease, types A and B. It is a genetically-inherited disease caused by a deficiency in the enzyme Sphingomyelinase, which causes the accumulation of Sphingomyelin in spleen, liver, lungs, bone marrow, and the brain, causing irreversible neurological damage. Of the two types involving Sphingomyelinase, type A occurs in infants. It is characterized by jaundice, an enlarged liver, and profound brain damage. Children with this type rarely live beyond 18 months. Type B involves an enlarged liver and spleen, which usually occurs in the pre-teen years. The brain is not affected. Most

Used for the annotation of gene products whose process is not known or cannot be inferred." Proteins with no known biological function can be categorized according to protein structural criteria (distinctive structural domains), source organism or subcellular location.

In humans, it is the only membrane phospholipid not derived from glycerol. Like all sphingolipids, SPH has a ceramide core (sphingosine bonded to a fatty acid via an amide linkage). In addition it contains one polar head group, which is either phosphocholine or phosphoethanolamine.

The H+-ATPase or proton pump creates the electrochemical gradients in the plasma membrane of plants, fungi, protists and many prokaryotes. Here proton gradients are used to drive secondary transport processes. As such it is essential for the uptake of most metabolites, and also for plant responses to the environment (e.g. movement of leaves). Interestingly H+-ATPases are specific for plants, fungi and protists and Na+/K+-ATPases are specific for animal cells. These two groups of P-type ATPases, although not from the same subfamily, seems to perform a complementary function in plants/fungi/protists and animal cells; namely the creation of an electrochemical gradient used as

The heads of glycolipids contain a sphingosine with one or several sugar units attached to it. The hydrophobic chains belong either to: two fatty acids - in the case of the phosphoglycerides. one FA and the hydrocarbon tail of sphingosine - in the case of sphingomyelin and the glycolipids.

Phospholipids and glycolipids consist of two long, nonpolar (hydrophobic) hydrocarbon chains linked to a hydrophilic head group. The heads of phospholipids are phosphorylated and they consist of either: Glycerol (and hence the name phosphoglycerides given to this group of lipids). Sphingosine (with only one member - sphingomyelin).

PLCs perform their catalytic function at the plasma membrane where their substrate PIP2 is present. This membrane docking is mediated mostly by lipid-binding domains (e.g. PH domain and C2 domain) that display affinity for different phospholipid components of the plasma membrane. It is important to note that research has also discovered that, in addition to the plasma membrane, PLCs also exist within other sub-cellular regions such as the cytoplasm and nucleus of the cell. At present, it is unclear exactly what the definitive roles for these enzymes in these cellular compartments are, particularly the nucleus.

Plasma or concentrated urine is deposited on a gel. With an electrical current the proteins are sorted in function of their size, after which antigens for each targeted type of immunoglobulin are deposited on the gel. Thus more or less narrow bands appear on the gel, marking the location of the various immunoglobulines. Immunofixation tends to replace Protein electrophoresis because : it is faster (results within three hours) ; it is somewhat more sensitive. Immunofixation may reveal an immunoglobulin missed out by Protein electrophoresis, especially at low concentrations (less than 1 gram/litre) ; it can be partially automated and can be used in

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