Glycolipids are important components of the membranes of brain and nerve cells in animals. They compose of sphingosine, a fatty acid, and sugars such as glucose or galactose. They resemble sphingomyelin, but with a sugar unit in place of the choline phosphate group.
Galactosylceramide
Cerebrosides are a class of glycosphingolipids containing a sphingosine core. The carbohydrate component of these compounds consists of a monosaccharide, most commonly galactose, and a fatty acid, usually ceramide. Cerebrosides are found in small amounts throughout the body, and are especially abundant in the white matter of the brain and in the cell membranes of many other tissues.
Cerebrosides form by attaching a sphingosine molecule to a fatty acid through an amide bond. Then, a sugar adds to the C1 of sphingosine, creating a glycosphingolipid. Monoglycosylceramide is a type of ceramide, found in non-neural tissues, including skin.
The CST reaction was performed in a total volume of 50 ul. The buffer contained 3′-phosphoadenosine-5′-phosphosulphate and galactosylceramide, both dissolved in a 1:1 mixture of chloroform and methanol. A concentration of 938 ng of human galactosylceramide sulphotransferase (GST) was added to the buffer. After 10 min of heating at 60 degC, the reaction was terminated.
Galactosylceramide has a unique structure. It is an acyl-sphingosine sphingosine molecule, attached to galactose by an amide linkage. It accounts for approximately 4% of the total lipids in myelin.
Glucosylceramide
Glucosylceramide (GlcCer) is a type of sphingolipid, found in the brain, spinal cord, and peripheral nerve cells. It is a versatile molecule that plays an important role in cell division, differentiation, and death.
Cerebrosides can acylate to fatty acids, allowing them to migrate quickly through the brain. One type of acylated cerebrosides has found in rat brains. These cerebrosides have been termed fast-migrating cerebrosides. An additional type of acylated cerebroside has isolated from the brains of equines.
Glucosylceramide, produced by the hydrolysis of glucosylceramide by a glycosidase enzyme known as GBA2. Some of the resulting ceramide then converts to sphingomyelin by sphingomyelinase 2, a co-located enzyme that also hydrolyses glucosylceramide. Moreover, cellular b-glucosylceramidase enzymes have the ability to transfer glucose from glucosylceramide to other lipids. Among the lipids that glucosylceramide can transfer to are cholesterol glucoside, ceramide, and sphingomyelin.
Glycosylceramide is the most common glycolipid in human brain tissue, found in all nerve tissues and found in very low levels in other organs. It makes up about 2% of dry weight of brain tissue and 12% of the white matter. Glycosylceramide is also a constituent of myelin, which is an important component of nerves.
Glucocerebroside
Glycolipids are a group of fatty acids with carbohydrate attachments that are present in animal cells. They provide energy and act as markers of cellular recongnition, found in the brain and in the myelin sheaths of nerves.
Cerebrosides are neutral glycosphingolipids that have a ceramide backbone and a monosaccharide in the head group. These compounds derive from various sources, including bacterial cells and eukaryotes, also found in plants, animals, and fungi.
Glycolipids derive from the parent base sphingosine. Glycolipids of the nervous system usually compose of galactose while those of the non-nervous system compose of glucose and erythrocytes. Glycocerebrosides and galactocerebrosides are two major types of cerebrosides.
Glycolipids are abundant in the skin and are found in high concentrations in human and animal tissues. Glycolipids are also present in the nervous system of animals and plant cells. They are found in apical plasma membrane domains of epithelial cells, intestinal cells, and urinary bladder cells.
Glycolipids are complex lipids, composed of fatty acid and carbohydrates, characterized by their high melting points and paracrystalline structure. The hydrogen bonds between polar hydrogens in the sugar and the hydroxy and amide groups of the ceramide moiety believe to contribute to the high transition temperature. Some cerebrosides contain several carbohydrates, called gangliosides.
Galactosylceramide in brain
Galactosylceramide is a biomarker of cellular health and has found in both brain and serum of mice. Its effects on behavior, neuropathology, and neuronal cell counts have been studied. Its impact on the lifespan of mice have also investigated.
The limit of detection for GC is 0.4 to 1.1 nmol/g brain tissue. It was determine using an ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS) method. The enzyme separates from isobaric galactoceramides and analysed in tandem mass spectrometry.
Ceramides compose of a fatty acid, linked to a fatty acid by an amide bond. The galactose residue is at the 1-hydroxyl moiety of ceramide. A enzyme called galactosylceramidase cleaves this residue.
Glucosylceramide synthase
Cerebrosides form when a cerebroside molecule converts into a ganglioside by the addition of sialic acid groups. These glycolipids embedd in the membranes of intralysosomes.
Glucosylceramide synthesizes from a-D-galactose in the marine sponge Bacteroides fragilis. This sponge contributes to the intestinal microflora in humans. The cerebrosides it produces contain saturated fatty acids, long-chain bases, and iso-methyl branches. Cerebrosides are present in trace amounts in mammalian cells and believe to play a role in the immune response.
Glucosylceramide is a lignin-like substance in the cell membrane that is essential for many functions, including intracellular membrane transport, cell proliferation, and survival. It also requires for various functions of the immune system. Overexpression of this molecule has associated with several disease states. Glucosylceramide has linked to increased resistance to chemotherapy and tumour progression, among other things.
Cerebrosides are important components of the cell membrane. Their structure is similar to glycolipids, but cerebrosides have a higher melting point. Moreover, cerebrosides have a high transition temperature. In humans, they are present in all nervous tissues and organs at low levels. In the brain, they constitute 2% to 12% of the dry weight of grey matter and up to 23% of the white matter. They also play a role in the insulation of axons.
Hydrophobic part of the lipid molecules
Cerebrosides are a class of natural products, derived from the hydrophobic part of lipid molecules. They isolate from diverse marine organisms and microbes. They have shown to have therapeutic potential against a variety of diseases, including cancer. Moreover, they are found to inhibit a number of viral and bacterial diseases, and they may also be effective against inflammation.
Lipid molecules found in biological membranes are highly polar, with a hydrophobic tail. The polar part of the molecule aligns with the polar aqueous environment, while the hydrophobic tail minimizes contact with water. This interaction between lipid molecules results in the formation of liposomes and micelles. These lipids can also assume a number of other aggregation states.
Membrane lipids compose of three families: sterols, phospholipids, and glycerols. Sterols are the most hydrophobic of the three, while fatty acids are the least hydrophobic. These two groups are similar to one another, though.
Intermolecular complex formation
Cerebrosides are glycolipids, found primarily in the brain and peripheral nervous tissue. These lipids contain a galactose molecule, which gives them their protective coating. Cerebrosides are also essential components of the myelin sheath, which is a protective membrane that surrounds nerve cells.
The majority of glycolipids are found in membrane structures within the cell. They synthesize in the golgi-apparatus and transport to membranes where they play critical roles in maintaining the bilayer. A small percentage is found in the soluble fraction of the cell.
Glycolipids can form intermolecular complexes with divalent cations. The process involves hydrophobic interactions between the headgroups of glycolipids. The carbohydrate headgroups of the lipid molecules coordinate with the divalent cation, which is a calcium ion.
The composition of cerebrosides varies in different organisms. Some contain only galactose-based fatty acids, while others have a high proportion of glucosylceramides. Cerebrosides from Japanese quail intestines, for example, contain mainly saturated fatty acids.
