Introduction to sphingolipids
Sphingolipids are of great interest to lipid biochemists because they have unique chemical properties (see image right and list below).
- The acyl-chains are linked by an amide bond
- The fatty acid component (black) is usually >18 carbons
- The long-chain base portion (green) contains a natural free hydroxy group
- The fatty acid is very often 2-hydroxy
- Numerous other modifications of the ceramide structure can occur (red)
- Headgroup R is either a hydroxy or a variety of carbohydrate or phospholipid structures
The answer to the Sphinx's sphingolipid riddle is Gangliosides or Glycosyl-inositol-phospho-ceramides (GIPCs). Both are highly glycosylated sphingolipids, so much so in fact that they may not soluble in traditional lipid solvents like chloroform. Confusingly perhaps, they frequently contain very long-chain fatty acids (VLCFA) coupled to the long-chain base (LCB) by an amide bond, which cannot be hydrolyzed effectively by mild base (unlike the fatty acids of glycerolipids). These highly amphipathic molecules (amphipathic meaning having both polar and non-polar components) are frequently found in the aqueous phase of lipid extracts (e.g. Bligh & Dyer) and require special extraction methods and analytical techniques.
| Generic structure of a sphingolipid |
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| Sphingolipids consist of a long-chain base (green) amide linked to a fatty acid (black). Various modifications can be made to the basic structure (red) including desaturations (4, 8 and n-9), hydroxylations (2 & 4) and headgroups (R). |
Sphingolipid portal
Below are links to many articles on plant sphingolipids, their structure, synthesis and biology. Use these to discover more about sphingolipids and our research projects involving plant sphingolipid metabolism.
History behind sphingolipids
So where did the name "sphingo" lipid come from anyway? When were they first discovered and why were people interested in them?
Structure of sphingolipids
Sphingolipids have a wide variety of different structures involving fatty acids, long-chain bases and carbohydrates. These combine to make up a complicated array of sphingolipids.
Sphingolipidomics
Measuring the amount and type of sphingolipid in any particular sample is a challenging task due to the large number of different compounds with different physical properties and their widely varying levels within a cell. This article explains how we do it and provides protocols and tips so you can also measure sphingolipids in your own lab.
Sphingolipid data
Examples of data from sphingolipidomics. What do the data tell us about the function and organization of sphingolipid metabolism and the role of sphingolipids in plant biollogy?
Plant Sphingolipids - latest papers
Metabolism of sphingolipids
The metabolism of sphingolipids is a complex web of reactions distributed around the cell. Lean more about individual reactions, the enzymes involved, genes and unique aspects of
plant sphingolipid synthesis.
Function of sphingolipids
So what do all those sphingolipids do anyway? Find out about their role in transport of proteins to the cell membrane, their organizing potential within membranes, the numerous signalling pathways that depend on sphingolipids (including programmed cell death) and more.