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Galactocerebroside
A galactosylceramide, or galactocerebroside is a type of cerebroside consisting of a ceramide with a galactose residue at the 1-hydroxyl moiety. The galactose is cleaved by galactosylceramidase. Galactosylceramide is a marker for oligodendrocytes in the brain, whether or not they form myelin. Additional images File:Sphingolipid.png, Sphingolipid See also * Alpha-Galactosylceramide * Krabbe disease * Myelin Myelin is a lipid-rich material that surrounds nerve cell axons (the nervous system's "wires") to insulate them and increase the rate at which electrical impulses (called action potentials) are passed along the axon. The myelinated axon can be ... References External links *CHEMBL110111 Glycolipids {{biochemistry-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebroside
Cerebrosides is the common name for a group of glycosphingolipids called monoglycosylceramides which are important components in animal muscle and nerve cell membranes. They consist of a ceramide with a single sugar residue at the 1-hydroxyl moiety. The sugar residue can be either glucose or galactose; the two major types are therefore called glucocerebrosides (a.k.a. glucosylceramides) and galactocerebrosides (a.k.a. galactosylceramides). Galactocerebrosides are typically found in neural tissue, while glucocerebrosides are found in other tissues. Structure The fundamental structure of a cerebroside is ceramide. Monoglycosyl and oligoglycosylceramides having a mono or polysaccharide bonded glycosidically to the terminal OH group of ceramide are defined as cerebrosides. Sphingosine is the main long-chain base present in ceramide. Galactosylceramide is the principal glycosphingolipid in brain tissue. Galactosylceramides are present in all nervous tissues, and can compose up to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myelin
Myelin is a lipid-rich material that surrounds nerve cell axons (the nervous system's "wires") to insulate them and increase the rate at which electrical impulses (called action potentials) are passed along the axon. The myelinated axon can be likened to an electrical wire (the axon) with insulating material (myelin) around it. However, unlike the plastic covering on an electrical wire, myelin does not form a single long sheath over the entire length of the axon. Rather, myelin sheaths the nerve in segments: in general, each axon is encased with multiple long myelinated sections with short gaps in between called nodes of Ranvier. Myelin is formed in the central nervous system (CNS; brain, spinal cord and optic nerve) by glial cells called oligodendrocytes and in the peripheral nervous system (PNS) by glial cells called Schwann cells. In the CNS, axons carry electrical signals from one nerve cell body to another. In the PNS, axons carry signals to muscles and glands or from senso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myelin
Myelin is a lipid-rich material that surrounds nerve cell axons (the nervous system's "wires") to insulate them and increase the rate at which electrical impulses (called action potentials) are passed along the axon. The myelinated axon can be likened to an electrical wire (the axon) with insulating material (myelin) around it. However, unlike the plastic covering on an electrical wire, myelin does not form a single long sheath over the entire length of the axon. Rather, myelin sheaths the nerve in segments: in general, each axon is encased with multiple long myelinated sections with short gaps in between called nodes of Ranvier. Myelin is formed in the central nervous system (CNS; brain, spinal cord and optic nerve) by glial cells called oligodendrocytes and in the peripheral nervous system (PNS) by glial cells called Schwann cells. In the CNS, axons carry electrical signals from one nerve cell body to another. In the PNS, axons carry signals to muscles and glands or from senso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceramide
Ceramides are a family of waxy lipid molecules. A ceramide is composed of N-acetylsphingosine and a fatty acid. Ceramides are found in high concentrations within the cell membrane of eukaryotic cells, since they are component lipids that make up sphingomyelin, one of the major lipids in the lipid bilayer. Contrary to previous assumptions that ceramides and other sphingolipids found in cell membrane were purely supporting structural elements, ceramide can participate in a variety of cellular signaling: examples include regulating differentiation, proliferation, and programmed cell death (PCD) of cells. The word ''ceramide'' comes from the Latin ''cera'' (wax) and ''amide''. Ceramide is a component of vernix caseosa, the waxy or cheese-like white substance found coating the skin of newborn human infants. Pathways for ceramide synthesis There are three major pathways of ceramide generation. First, the sphingomyelinase pathway uses an enzyme to break down sphingomyelin in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galactose
Galactose (, '' galacto-'' + '' -ose'', "milk sugar"), sometimes abbreviated Gal, is a monosaccharide sugar that is about as sweet as glucose, and about 65% as sweet as sucrose. It is an aldohexose and a C-4 epimer of glucose. A galactose molecule linked with a glucose molecule forms a lactose molecule. Galactan is a polymeric form of galactose found in hemicellulose, and forming the core of the galactans, a class of natural polymeric carbohydrates. D-Galactose is also known as brain sugar since it is a component of glycoproteins (oligosaccharide-protein compounds) found in Nerve tissue, nerve tissue. Etymology The word ''galactose'' was coined by Charles Weissman in the mid-19th century and is derived from Greek ''galaktos'' (of milk) and the generic chemical suffix for sugars ''-ose''. The etymology is comparable to that of the word '' lactose'' in that both contain roots meaning "milk sugar". Lactose is a disaccharide of galactose plus glucose. Structure and isomerism Gal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galactosylceramidase
Galactosylceramidase (or galactocerebrosidase) is an enzyme that in humans is encoded by the ''GALC'' gene. Galactosylceramidase is an enzyme which removes galactose from ceramide derivatives (galactosylceramides). Galactosylceramidase is a lysosomal protein which hydrolyzes the galactose ester bonds of galactosylceramide, galactosylsphingosine, lactosylceramide, and monogalactosyldiglyceride. Mutations in this gene have been associated with Krabbe disease Krabbe disease (KD) (also known as globoid cell leukodystrophy or galactosylceramide lipidosis) is a rare and often fatal lysosomal storage disease that results in progressive damage to the nervous system. KD involves dysfunctional metabolism of ..., also known as galactosylceramide lipidosis. References Further reading * * * * * * * * * * * * * * * * * * * * External links GeneReviews/NCBI/NIH/UW entry on Krabbe disease OMIM entries on Krabbe disease* PDBe-KBprovides an overview of all the structure information avai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligodendrocytes
Oligodendrocytes (), or oligodendroglia, are a type of neuroglia whose main functions are to provide support and insulation to axons in the central nervous system of jawed vertebrates, equivalent to the function performed by Schwann cells in the peripheral nervous system. Oligodendrocytes do this by creating the myelin sheath. A single oligodendrocyte can extend its processes to 50 axons, wrapping approximately 1 μm of myelin sheath around each axon; Schwann cells, on the other hand, can wrap around only one axon. Each oligodendrocyte forms one segment of myelin for several adjacent axons. Oligodendrocytes are found only in the central nervous system, which comprises the brain and spinal cord. These cells were originally thought to have been produced in the ventral neural tube; however, research now shows oligodendrocytes originate from the ventral ventricular zone of the embryonic spinal cord and possibly have some concentrations in the forebrain. They are the last cell t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphingolipid
Sphingolipids are a class of lipids containing a backbone of sphingoid bases, a set of aliphatic amino alcohols that includes sphingosine. They were discovered in brain extracts in the 1870s and were named after the mythological sphinx because of their enigmatic nature. These compounds play important roles in signal transduction and cell recognition. Sphingolipidoses, or disorders of sphingolipid metabolism, have particular impact on neural tissue. A sphingolipid with an R group consisting of a hydrogen atom only is a ceramide. Other common R groups include phosphocholine, yielding a sphingomyelin, and various sugar monomers or dimers, yielding cerebrosides and globosides, respectively. Cerebrosides and globosides are collectively known as glycosphingolipids. Structure The long-chain bases, sometimes simply known as sphingoid bases, are the first non-transient products of '' de novo'' sphingolipid synthesis in both yeast and mammals. These compounds, specifically known as phy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-Galactosylceramide
''alpha''-Galactosylceramide (α-GalCer, KRN7000) is a synthetic glycolipid derived from structure-activity relationship studies of galactosylceramides isolated from the marine sponge '' Agelas mauritianus''. α-GalCer is a strong immunostimulant Immunostimulants, also known as immunostimulators, are substances (drugs and nutrients) that stimulate the immune system by inducing activation or increasing activity of any of its components. One notable example is the granulocyte macrophage colon ... and shows potent anti-tumour activity in many ''in vivo'' models. Immunostimulatory properties α-GalCer is a potent activator of iNKT cells, and a model CD1d antigen. The invariant T cell receptor of the iNKT cell is able to bind the CD1d:glycolipid complex leading to iNKT cell activation in both mice and humans. Adjuvant activity In combination with a peptide antigen, α-GalCer is able to stimulate a strong immune response against the epitope. The CD1d:glycolipid:TCR interaction ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Krabbe Disease
Krabbe disease (KD) (also known as globoid cell leukodystrophy or galactosylceramide lipidosis) is a rare and often fatal lysosomal storage disease that results in progressive damage to the nervous system. KD involves dysfunctional metabolism of sphingolipids and is inherited in an autosomal recessive pattern. The disease is named after the Danish neurologist Knud Krabbe (1885–1961). Signs and symptoms Symptoms in asymptomatic infantile-onset (<12 months after birth) and later-onset Krabbe disease present themselves differently. Of individuals with infantile-onset Krabbe disease, 85–90% display progressive neurologic deterioration in infancy and death before the age of two. Symptoms include , s, limb stiffness, < ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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