Sulfatides synthesis

Sulfogalactosylceramide (Sulfatide) synthesis and degradation in CNS and PNS. Regional and cellular abnormalities may also be related to defects in the synthesis of sulfatides. Sulfatides, coded by the galactosylceramide sulfotransferase gene, are essential for maintenance of Na" ion channels on myelinated axons but are not required for initial clusto formation (Ishibashi et al., 2002). Mice deficient for this gene are unable to synthesize sulfatides. They display abnormal paranodal junctions in the CNS and PNS, whereas their compact myelin is preserved (Honke et al.,... 

Insulin-dependent diabetes mellitus is an autoimmune disease and high titers of auto-antibodies against both insulin and sulfatide were found in patients with insulin-dependent diabetes (Andersson et ah, 2002 Buschard et al., 2005). Sulfatide and insulin are present in the same cellular compartments and share the same intracellular trafficking pathways (Buschard et ah, 2005 Fredman et ah, 2000). The inhibition of sulfatide synthesis with chloroquine and fumo-nisine B1 leads to inhibition of insulin granule formation in vivo (Fredman et al.,... 

Ramakrishnan H., Hedayati K.K., Lullmann-Rauch R., Wessig C., Fewou S.N., Maier H., Goebel H.H., Gieselmann V., Eckhardt M., Increasing sulfatide synthesis in myelinforming cells of arylsulfatase A-deficient mice causes demyelination and neurological symptoms reminiscent of human metachromatic leukodystrophy. Journal of Neuroscience 27 (2007) 9482-9490. 

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... 

The assays for the enzyme synthesis of sulfogalactosyl-glycerolipid, sulfatides and galactocerebrosides were carried out as previously described respectively by Subba Rao, et al. (28) Sarlieve, et al. 05, 29), and Neskovic, et al. (30). The assay for 2, 3 cyclic nucleotide phosphohydrolase was performed according to the method of Prohaska, et al. (31). EL coli. alkaline phosphatase type III-S, 2, 3 -cAMP, and sodium deoxycholate were obtained from Sigma (St. Louis, Mo.). Protein was determined by the method of Lowry, et al. (32) with crystalline bovine serum albumin as the standard. 

The vitamin also activates serine palmitoyltransferase, the first enzyme of phosphosphingolipid synthesis, and in bacteria it can, together with inorganic phosphate, replace part of the ATP requirement of galactocerebroside sulfo-transferase (Tsaioun, 1999). In animals, lipid sulfatides are decreased in vitamin K deficiency and increased with higher intakes (Sundaram et al., 1996). 

Estimates of the rate of myelin synthesis can be obtained in vitro from the measurement of cerebroside synthesis, which increases fourfold from day 10 to day 20 in the rat and then slowly decreases along with the overall rate of myelin synthesis. In vivo studies employing radiolabeled precursors of specific myelin components, such as sulfate into sulfatide, yield results similar to those obtained in vitro. In situ studies with tissue slices confirm in vitro and in vivo experiments. These studies also indicate that the appearance of... 

Sulfated glycosphingolipids. Sulfatide (3 -sulfo-GalCer) synthesis is catalyzed by GalCer sulfatotransferase, which utilizes the activated sulfate donor 3 -phosphoadenosine-5 -phosphosulfate. The cDNA encoding the sulfotransferase has been cloned (K. Honke,... 

The most common cerebrosides include galactosylceramide, glucosylceramide, and sulfatides (see Figure 19.14 for synthesis scheme). Sulfatides are made by transferring a sulfate group to a galactosylceramide (Figure 19.14). 

Fig. 33.34. The synthesis of 3 -phosphoadenosine 5 -phosphosulfate (PAPS), an active sulfate donor. PAPS donates sulfate groups to cerebrosides to form sulfatides and is also involved in glycosaminoglycan biosynthesis (see Chapter 49). Ad = adenosine.

Results of relaxometry indicate a dysmyelination , as originally described by Hommes and Matsuo (1987) in the hyperphenylalaninemic rat, namely that the decreased synthesis of sulfatides and other myelin compartments is associated with an increased myelin turnover, leading to disruption splaying of myelin lamellae associated with increased water content. 

The sulfatide isolated was soluble in chloroform-methanol (2—1) and failed to partition into an aqueous phase. Further identification of the sulfolipid was not made. Goldberg (1961) has postulated several pathways which may be involved in cerebroside sulfate synthesis. The initial steps are the activations of sulfate to 3 -phosphoadenosine-5 -phosphosulfate, i.e., PAPS, as described by Bandurski et al. (1956, 1958), Wilson and Bandurski (1956), and Robbins and Lipmann (1956, 1958a, b). 

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