Sphingolipids hydrolysis

Table II. Genetic Lipid Storage Diseases Involving Sphingolipid Hydrolysis ...

Gatt, S., 1966fl, Enzymatic hydrolysis of sphingolipids. Hydrolysis of ceramide glucoside by an enzyme from ox brain, Biochem. J. 101 687-691. 

Certain classes of lipids are susceptible to degradation under specific conditions. For example, all ester-linked fatty acids in triacylglycerols, phospholipids, and sterol esters are released by mild acid or alkaline treatment, and somewhat harsher hydrolysis conditions release amide-bound fatty acids from sphingolipids. Enzymes that specifically hydrolyze certain lipids are also useful in the determination of lipid structure. Phospholipases A, C, and D (Fig. 10-15) each split particular bonds in phospholipids and yield products with characteristic solubilities and chromatographic behaviors. Phospholipase C, for example, releases a water-soluble phosphoryl alcohol (such as phosphocholine from phosphatidylcholine) and a chloroform-soluble diacylglycerol, each of which can be characterized separately to determine the structure of the intact phospholipid. The combination of specific hydrolysis with characterization of the products by thin-layer, gas-liquid, or high-performance liquid chromatography often allows determination of a lipid structure. 

Evidence suggests that dietary sphingolipids, acting through their hydrolysis products, ceramide and sphingosine, can inhibit the development of colon cancer (Duan, 1998 Vesper et al., 1999). In milk fat, sphingomyelin is by far the predominant sphingolipid. 

Yavin, E., and Gatt, S., 1969, Enzymatic hydrolysis of sphingolipids. 8. Further purification and properties of rat brain ceramidase. Biochemistry 8 1692-1698. 

Alkaline hydrolysis (e.g., the Schmidt-Thann-hauser procedure, which employs 1 N KOH at 37°C for 24 hr) cleaves most ester bonds but leaves the amide groups in sphingolipids intact. Alcoholic alkali may be necessary with lipid mixtures that do not disperse readily into aqueous solutions. Potassium hydroxide is preferable because it is more soluble in alcohol than NaOH similarly, potassium salts of fatty acids are more soluble than their equivalent sodium salts. 

Zschoche A, Furst W, Schwarzmann G, San-hoff K (1994) Hydrolysis of lactosylceramide by human galacrtosylceramidase and GM1-/1-galactosidase in a detergent-free system and its stimulation by sphingolipid activator protein, sap-B and sup-C. Activator proteins stimulate lactosylceramide hydrolysis. Eur J Biochem 222 83-90... 

In the Table I are listed some sphingosines, dihydrosphingosines, phytosphingosines, and so on, that have been isolated by hydrolysis of sphingolipids of animal or plant origin. Table II lists some derivatives of these compounds that can be obtained from the natural sphingosines by such simple chemical transformations as acylation. 

The diastereoisomeric configuration of the sugar-free cerebrosides (ceramides) was determined by Carter and coworkers,80 and found to be erythro, in accordance with the structure of sphingosine, which is isolated after drastic hydrolysis of sphingolipid mixtures or purified cerebrosides with acid. 

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