P. Braun*, P. Morell, N. Radin
Jan 25, 1970
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0
Influential Citations
94
Citations
Quality indicators
Journal
The Journal of biological chemistry
Abstract
Abstract Microsomal preparations from mouse brain were found to synthesize 3-ketodihydrosphingosine (2-amino-1-hydroxy-octadecan-3-one) from l-serine and palmitoyl coenzyme A. The reaction appeared to require pyridoxal phosphate but no metal ion. In the presence of TPNH the major sphingolipid product was dihydrosphingosine; smaller amounts of N-acyldihydrosphingosine and N-acylsphingosine were also found. The kinetics of utilization of 14C-palmitoyl-CoA indicated that accumulation of dihydrosphingosine was followed by acylation to form the ceramide. Sphingosine, which was not accumulated in detectable amounts, was apparently acylated much more rapidly. Stearoyl-CoA also reacted, producing the corresponding C20-sphingolipids, but oleoyl-CoA and lignoceroyl-CoA were inactive. At the optimal acyl-CoA concentration, stearoyl-CoA was less than half as effective as palmitoyl-CoA in the formation of ketodihydrosphingosine. The various labeled sphingolipids formed were separated by thin layer chromatography in several systems and identified by radioautography; acetyl and dinitrophenyl derivatives were also chromatographed. Of particular value was the use of borate-containing thin layer plates, which effectively separated fatty acyl sphingosine from fatty acyl dihydrosphingosine.