scholarly journals Different metabolic recycling of the lipid components of exogenous sulphatide in human fibroblasts

1988 ◽  
Vol 252 (2) ◽  
pp. 375-379 ◽  
Author(s):  
M Trinchera ◽  
U Wiesmann ◽  
M Pitto ◽  
D Acquotti ◽  
R Ghidoni
Keyword(s):  
Fatty Acid ◽  
Human Fibroblasts ◽  
Total Lipid Extract ◽  
Phospholipid Biosynthesis ◽  
Metabolic Fate ◽  
Long Chain Base ◽  
Cultured Human Fibroblasts ◽  
Almost All ◽  
Long Chain ◽  
Ceramide Moiety

Cultured human fibroblasts were fed with two differently labelled sulphatide molecules [one labelled on C-3 of the sphingosine (Sph) moiety [(Sph-3H]sulphatide), the second on C-1 of stearic acid [(stearoyl-14C]sulphatide)], and the intracellular metabolic fate of radioactivity was monitored. Incorporated radioactivity was almost all recovered in the total lipid extract, regardless of the labelling position of the added sulphatide; however, large differences in the level of incorporation occurred among labelled glycosphingolipids. For example, sphingomyelin was present as the major radiolabelled lipid after [Sph-3H]-sulphatide incubation, but was detectable only in trace amounts after [stearoyl-14C]sulphatide administration; in the latter case the radioactivity was located predominantly in glycerophospholipids. From this finding it can be inferred that the free long-chain base (sphingosine) that originates from lysosomal catabolism of sulphatide is mainly, and quite specifically, utilized for sphingomyelin biosynthesis, whereas the ceramide moiety is not; conversely the fatty acid released from ceramide is non-specifically re-utilized for phospholipid biosynthesis.

scholarly journals Human fibroblasts in culture metabolize differently exogenous G(M3) ganglioside species containing C18 and C20 sphingosine.

1998 ◽  
Vol 45 (2) ◽  
pp. 385-392
Author(s):  
V Chigorno ◽  
M Valsecchi ◽  
S Sonnino
Keyword(s):  
Human Fibroblasts ◽  
Decisive Role ◽  
Metabolic Fate ◽  
Base Content ◽  
Long Chain Base ◽  
Complex Lipids ◽  
Sphingolipid Biosynthesis ◽  
Ganglioside Species ◽  
Long Chain ◽  
Complex Sphingolipids

Preparation of radioactive GM3 species containing isotopically labeled C18 sphingosine or C20 sphingosine is reported and their use for studying some aspects of the sphingolipid biosynthesis in cells is discussed. Human fibroblasts in culture that have only C18 sphingolipids and GM3 as the major gangliosides, were fed with the two radioactive GM3 species. The radioactive gangliosides were taken up by the cells and metabolized. The analyses of the radioactivity metabolic fate, in this model provides the following information. i--About 70-80% of the total catabolic sphingosine is re-cycled for biosynthesis of complex sphingolipids. ii--A small amount of the catabolic C20 sphingosine was re-cycled for biosynthesis of C20 sphingolipids, thus yielding complex lipids that are not naturally present in fibroblast cells. iii--A regulatory step in the biosynthesis of sphingolipid species differring long chain base content, C18 or C20 sphingosine, is in some way involved in the first steps of sphingolipid biosynthesis, and thus plays a decisive role in the availability of the long chain bases.

Ceramid-1-phosphoethanolamine aus Myxococcus stipitatus/ Ceramide-1-phosphoethanolamines from Myxococcus stipitatus

1988 ◽  
Vol 43 (8) ◽  
pp. 1063-1068 ◽  
Author(s):  
J. Stein ◽  
H. Budzikiewicz
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Component ◽  
Acid Component ◽  
Chain Base ◽  
Long Chain Base ◽  
Ceramide 1 ◽  
Long Chain

AbstractThe structures of six ceramide-1-phosphoethanolamines have been elucidated which differ in the long chain base as well as in the fatty acid component

scholarly journals A novel pathway of ceramide metabolism in Saccharomyces cerevisiae

2012 ◽  
Vol 447 (1) ◽  
pp. 103-114 ◽  
Author(s):  
Natalia S. Voynova ◽  
Christine Vionnet ◽  
Christer S. Ejsing ◽  
Andreas Conzelmann
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Biosynthesis ◽  
Living Cells ◽  
Tandem Ms ◽  
Acid Biosynthesis ◽  
Acceptor Substrate ◽  
Long Chain Base ◽  
Hydrophobic Compound ◽  
Hydrolysis Of ◽  
Long Chain

The hydrolysis of ceramides in yeast is catalysed by the alkaline ceramidases Ypc1p and Ydc1p, two highly homologous membrane proteins localized to the ER (endoplasmic reticulum). As observed with many enzymes, Ypc1p can also catalyse the reverse reaction, i.e. condense a non-esterified fatty acid with PHS (phytosphingosine) or DHS (dihydrosphingosine) and thus synthesize ceramides. When incubating microsomes with [3H]palmitate and PHS, we not only obtained the ceramide PHS–[3H]C16:0, but also a more hydrophobic compound, which was transformed into PHS–[3H]C16:0 upon mild base treatment. The biosynthesis of a lipid with similar characteristics could also be observed in living cells labelled with [14C]serine. Its biosynthesis was dependent on the diacylglycerol acyltransfereases Lro1p and Dga1p, suggesting that it consists of an acylceramide. The synthesis of acylceramide could also be monitored using fluorescent NBD (7-nitrobenz-2-oxa-1,3-diazole)–ceramides as an acceptor substrate for microsomal assays. The Lro1p-dependent transfer of oleic acid on to NBD–ceramide was confirmed by high-resolution Fourier transform and tandem MS. Immunopurified Lro1p was equally able to acylate NBD–ceramide. Lro1p acylates NBD–ceramide by attaching a fatty acid to the hydroxy group on the first carbon atom of the long-chain base. Acylceramides are mobilized when cells are diluted into fresh medium in the presence of cerulenin, an inhibitor of fatty acid biosynthesis.

scholarly journals Recycling of glucosylceramide and sphingosine for the biosynthesis of gangliosides and sphingomyelin in rat liver

1990 ◽  
Vol 270 (3) ◽  
pp. 815-820 ◽  
Author(s):  
M Trinchera ◽  
R Ghidoni ◽  
S Sonnino ◽  
G Tettamanti
Keyword(s):  
Fatty Acid ◽  
Intravenous Injection ◽  
Rat Liver ◽  
Sugar Residue ◽  
Gm1 Ganglioside ◽  
Chain Base ◽  
Neutral Glycosphingolipids ◽  
Long Chain Base ◽  
Ganglioside Biosynthesis ◽  
Long Chain

It was previously shown that sphingomyelin and gangliosides can be biosynthesized starting from sphingosine or sphingosine-containing fragments which originated in the course of GM1 ganglioside catabolism. In the present paper we investigated which fragments were specifically re-used for sphingomyelin and ganglioside biosynthesis in rat liver. At 30 h after intravenous injection of GM1 labelled at the level of the fatty acid ([stearoyl-14C]GM1) or of the sphingosine ([Sph-3H]) moiety, it was observed that radioactive sphingomyelin was formed almost exclusively after the sphingosine-labelled-GM1 administration. This permitted the recognition of sphingosine as the metabolite re-used for sphingomyelin biosynthesis. Conversely, gangliosides more complex than GM1 were similarly radiolabelled after the two treatments, thus ruling out sphingosine re-utilization for ganglioside biosynthesis. For the identification of the lipid fragment re-used for ganglioside biosynthesis, we administered to rats neutral glycosphingolipids (galactosylceramide, glucosylceramide and lactosylceramide) each radiolabelled in the sphingosine moiety or in the terminal sugar residue. Thereafter we compared the formation of radiolabelled gangliosides in the liver with respect to the species administered and the label location. After galactosylceramide was injected, no radiolabelled gangliosides were formed. After the administration of differently labelled glucosylceramide, radiolabelled gangliosides were formed, regardless of the position of the label. After lactosylceramide administration, the ganglioside fraction became more radioactive when the long-chain-base-labelled precursors were used. These results suggest that glucosylceramide, derived from glycosphingolipid and ganglioside catabolism, is recycled for ganglioside biosynthesis.

Trifluoperazine increases fatty acid turnover in phospholipids in cultured human fibroblasts

Lipids ◽  
1988 ◽  
Vol 23 (5) ◽  
pp. 419-423 ◽  
Author(s):  
Cecile Mazière ◽  
Jean-Claude Mazière ◽  
Liliana Mora ◽  
Martine Auclair ◽  
Jacques Polonovski
Keyword(s):  
Fatty Acid ◽  
Human Fibroblasts ◽  
Fatty Acid Turnover ◽  
Cultured Human Fibroblasts

LIPIDS OF HALOBACTERIUM CUTIRUBRUM

1962 ◽  
Vol 40 (1) ◽  
pp. 69-81 ◽  
Author(s):  
S. N. Sehgal ◽  
M. Kates ◽  
N. E. Gibbons
Keyword(s):  
Fatty Acid ◽  
Phosphatidyl Inositol ◽  
Dry Weight ◽  
Weight Basis ◽  
Carotenoid Pigments ◽  
Total Lipids ◽  
Phosphatidyl Glycerol ◽  
Alkyl Groups ◽  
Almost All ◽  
Long Chain

Cells of Halobacterium cutirubrum contain about 2% of total lipids (including pigments) on a salt-free, dry weight basis. Almost all of the lipids (93%) are phosphatides, the remainder being carotenoid pigments. The phosphatide components are unusual in that they contain almost no fatty acid ester groups, but instead appear to have long-chain alkyl groups joined by ether linkages to glycerol. Most of the phosphatide fraction (73%) consists of a single component which is believed to be a long-chain ether analogue of diphosphatidyl glycerol. Small amounts of lecithin, lysolecithin, phosphatidyl inositol, and phosphatidyl glycerol also appear to be present.

LIPIDS OF HALOBACTERIUM CUTIRUBRUM

1962 ◽  
Vol 40 (1) ◽  
pp. 69-81 ◽  
Author(s):  
S. N. Sehgal ◽  
M. Kates ◽  
N. E. Gibbons
Keyword(s):  
Fatty Acid ◽  
Phosphatidyl Inositol ◽  
Dry Weight ◽  
Weight Basis ◽  
Carotenoid Pigments ◽  
Total Lipids ◽  
Phosphatidyl Glycerol ◽  
Alkyl Groups ◽  
Almost All ◽  
Long Chain

Cells of Halobacterium cutirubrum contain about 2% of total lipids (including pigments) on a salt-free, dry weight basis. Almost all of the lipids (93%) are phosphatides, the remainder being carotenoid pigments. The phosphatide components are unusual in that they contain almost no fatty acid ester groups, but instead appear to have long-chain alkyl groups joined by ether linkages to glycerol. Most of the phosphatide fraction (73%) consists of a single component which is believed to be a long-chain ether analogue of diphosphatidyl glycerol. Small amounts of lecithin, lysolecithin, phosphatidyl inositol, and phosphatidyl glycerol also appear to be present.

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