Biosynthesis of sphingolipids

FIGURE 25.25 Biosynthesis of sphingolipids in animals begins with the 3-ketosphinga-nine synthase reaction, a PLP-dependent condensation of palmitoyl-CoA and serine. Subsequent rednction of the keto group, acylation, and desatnration (via rednction of an electron acceptor, X) form ceramide, the precnrsor of other sphingolipids. 

Lehtonen, J.Y.A., Horiuchi, M., Daviet, L., AMshita, M. and Dzau, V.J., 1999, Activation of the de novo biosynthesis of sphingolipids mediates angiotensin 11 type 2 receptor-induced apoptosis. J. Biol. Chem. 274 16901-16906. 

FIGURE 21-31 Biosynthesis of sphingolipids. Condensation of palmitoyl-CoA and serine followed by reduction with NADPH yields sphinganine, which is then acylated to N-acylsphinganine (a ceramide). In animals, a double bond (shaded pink) is created by a mixed-function oxidase, before the final addition of a head group phosphatidylcholine, to form sphingomyelin glucose, to form a cerebroside. 

Sphingolipids comprise glycolipids (gangliosides and cerebrosides) and the phospholipid, sphingomyelin. These compounds, too, are important membrane constituents. The biosynthesis of sphingolipids involves the common intermediate ceramide (Fig. 13-15). 

See also Fatty Acids, Table 10.1, Synthesis of Long Chain Fatty Acids, Fatty Acid Desaturation, Palmitate Synthesis from Acetyl-CoA, Biosynthesis of Sphingolipids, 3-Ketosphinganine... 

How does the biosynthesis of sphingolipids take place Fatty acids are linked to a sphingosine backbone molecule, producing ceramides. Other moieties, including sugars, are added, producing gangliosides and other compounds. 

The biosynthesis of sphingolipids has been studied in mammalian systems (47) and in yeast (73). They are constructed by condensation of the co-enzyme A derivative of a long chain fatty acid, usually palmitate (C-16) with serine with concomitant loss of the carboxyl group of serine. The ketone group is then reduced to give sphinganine, a close structural... 

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