Solubilization and partial characterization of fatty acyl-CoA:sphingosine acyltransferase (ceramide synthetase) from rat liver and brain.
Lignoceroyl-CoA:sphingosine lignoceroyltransferase, which catalyzes synthesis of lignoceroylsphingosine, the ceramide that is a major component of sphingolipids in mammalian tissues, has been solubilized from microsomes of rat brain and liver and partially purified. The microsomes were treated with 1 M sodium thiocyanate in N,N-bis(2-hydroxyethyl)glycine (Bicine) buffer containing 20% glycerol. The supernatant fraction obtained after centrifugation was fractionated by Sepharose CL-4B gel filtration. The ceramide synthetase activity was recovered in a small fraction containing high molecular weight proteins. Analysis of proteins and lipids indicated that the fraction was not simply a fragment of microsomes. The activity for synthesis of lignoceroylsphingosine, which is abundant in nervous system, was compared with that for the synthesis of stearoylsphingosine, which is more enriched in extraneural sphingolipids, in brain and liver microsomes. Despite the difference in relative abundance of molecular species of ceramides in these tissues, the activity for lignoceroylsphingosine synthesis was not more enriched in brain than in liver.
D000214:Acyl Coenzyme A / Q000378:metabolism; D000217:Acyltransferases / Q000032:analysis / Q000302:isolation & purification*; D000818:Animals; D001921:Brain / Q000201:enzymology*; D002518:Ceramides / Q000096:biosynthesis; D002850:Chromatography, Gel; D008099:Liver / Q000201:enzymology*; D011506:Proteins / Q000032:analysis; D051381:Rats; D012995:Solubility; D051049:Sphingosine N-Acyltransferase
D000214:Acyl Coenzyme A; D002518:Ceramides; D011506:Proteins; D000217:Acyltransferases; D051049:Sphingosine N-Acyltransferase