Ceramide galactosylation

Mutant or knockout mice defective in specific enzymes involved in lipid synthesis have provided powerful tools for genetic analysis of lipid function in the nervous system. For example, disruption of the genes for ceramide galactosyl transferase or galactosyl ceramide sulfotransferase,... 

A few GSLs are based on galactosyl ceramide rather than glu-cosyl ceramide. Galactosyl ceramide synthase, unlike glucosyl... 

Sulfatide (ceramide galactosyl-3 -sulfate) is present in many tissues. Accumulation of sulfatide and related compounds resulting from the storage disorder metachromatic leukodystrophy was followed by a normal-phase separation on a silica column (A = 229 nm) using a 16-min 99/1 - 80/20 hexane/dioxane gradient [718]. Good resolution between sulfated and six related compounds was obtained and the last analyte of interest eluted in <10 min. 

The glycosphingolipids (GSLs) are sugar-containing lipids built on a backbone of ceramide they include galactosyl- and glucosylceramide (cerebrosides) and the gangliosides. Their structures are described in Chapter 14. They are mainly located in the plasma membranes of cells. 

Central nervous system myelin is enriched in certain lipids. Table 4-1 lists the composition of bovine, rat, and human myelin compared to bovine and human white matter, human gray matter, and rat whole brain [1] (see Ch. 3). While there are no absolutely myelin-specific lipids, cerebroside (galactosyl ceramide) is the most typical of myelin. With the exception of early development,... 

The lactosyl ceramide analogue (39 c) was also obtained by condensation, in acetone-methanol, of 4-0-triflyl galactosyl sphingosine (34c) with thiogalactose (8 c) generated in situ from the corresponding pseudothiourea derivative [38]. 

GM, Galactosyl-A/-acetylgalactosaminyl-(neuraminosyl)-galactosyl- glucosyl-ceramide... 

GD3 (disialohematoside) Neuraminosyl-(2 -> 8)-neuraminosyl-(2 - 3)-galactosyl-glucosyl-ceramide... 

GM, Galactosyl-iV-acetylgalactosaminyl-(neuraminosyl)-galactosy 1-glucosy 1-ceramide... 

Glycolipids are important constituents of the plasma membranes, of the endoplasmic reticulum, and of chloroplasts. The cerebrosides and their sulfate esters, the sulfatides, are especially abundant in myelin. In plant membranes, the predominant lipids are the galactosyl diglycerides.29 74 The previously described ether phospholipids (archaebacteria), ceramide arnino-ethylphosphonate (invertebrates), and sulfolipid (chloroplasts) are also important membrane components. 

A partial synthesis of cerebroside sulfate [ sulfatide, the glycoside of ceramide with galactose 3-sulfate, (90)] was achieved [90] by acylating the sphingosine galactosyl 3-sulfate (89) (obtained by basic hydrolysis of natural sulfatide) with palmitoyl chloride or D-2-acetoxypalmitoyl chloride (and subsequent basic hydrolysis of the... 

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