Galactose cerebroside

Prepare a 5 mg/ml liposome construction in 20 mM sodium phosphate, 0.15 M NaCl, pH 7.4, containing, on a molar ratio basis, a mixture of PC cholesterol PG other glycolipids of 8 10 1 2. The other glycolipids that can be incorporated include phosphatidyl inositol, lactosylceramide, galactose cerebroside, or various gangliosides. Other liposome compositions may be used, for example, recipes without cholesterol, as long as a periodate-oxidizable component... 

Ceramide galactoside (galactose cerebroside) is the principal cerebroside present in the central nervous system and found in high concentration in the myelin sheath. This compound has been demonstrated to accumulate in the brain of patients with Krabbes disease (Austin, 1963). 

D-Galactose H HO HO H HOH2 C—C—C—C—C—CHO HO H H HO widespread in plants lactose ovomucoid cerebrosides albumin gland of snail frog and toad spawn beef lung... 

Reaction (1) is irreversible the enzyme galactokinase has been found in mammalian liver, brain, and erythrocytes, as well as in certain yeasts and other microorganisms. UDPGal, the main product of reaction (2), is the intermediate by means of which the body incorporates galactose into cerebrosides and, probably, other galactolipids, mucopolysaccharides, and lactose galactose-l-phosphate uridyl transferase occurs in the liver, to a lesser extent in red cells, and probably in other tissues. 

Cerebrosides contain a ceramide unit and either a glucose or galactose residue. 

Figure 12.14 Monoglycosyl ceramides (cerebrosides). R is an acyl chain. The carbohydrate residue of galactose is shown although this may be replaced by another hex-ose. Glycosyl ceramides containing between two and six carbohydrate residues are also found but only the mono derivatives are referred to as cerebrosides.

Arylsulfatase [EC 3.1.6.1 ], also known simply as sulfatase, catalyzes the hydrolysis of a phenol sulfate, thereby producing a phenol and sulfate. This enzyme classification represents a collection of enzymes with rather similar specificities. (1) Steryl-sulfatase [EC3.1.6.2],also referred to as arylsulfatase C and steroid sulfatase, catalyzes the hydrolysis of 3-j8-hydroxyandrost-5-en-17-one 3-sulfate to 3-j8-hydroxyandrost-5-en-17-one and sulfate. The enzyme utilizes other steryl sulfates as substrates. (2) Cere-broside-sulfatase [EC 3.1.6.8], or arylsulfatase A, catalyzes the hydrolysis of a cerebroside 3-sulfate to yield a cerebroside and sulfate. The enzyme will also hydrolyze the galactose 3-sulfate bond present in a number of lipids. In addition, the enzyme will also hydrolyze ascorbate 2-sulfate and other phenol sulfates. 

This enzyme [EC 3.1.6.8], also known as arylsulfatase A, catalyzes the hydrolysis of a cerebroside 3-sulfate to produce a cerebroside and sulfate. The enzyme will also catalyze analogous reactions on the galactose 3-sulfate residues in a number of lipids as well as on ascorbate 2-sulfate and many phenol sulfates. 

The galactose bears a 3-sulfate group in cerebroside sulfatides, e.g., in lactosyl ceramide sulfate ... 

From the sponge M. incrustans, two cerebrosides and a polar glycolipid were isolated.78 Both cerebrosides contain galactose and sphingosine, but differ in the nature of their fatty acids the less polar cerebroside contains normal, and the more polar, monohydroxy, acids. The structure of the polar glycolipid was not established, but it was shown to contain sphingosine, fatty acids, galactose, arabinose, fucose, and phosphorus.78... 

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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