Etherphospholipids are a class of phospholipids characterised by the presence of an ether bond at the sn-1 position on the glycerol backbone. (Brites et al 2004)
Biosynthesis of these etherphospholipids starts in the peroxisomes before a precursor molecule produced is transported for completion in the endoplasmic reticulum (Thai et al 2001). The Biosynthesis Process. Step 1: Acylation of Dihydroxyacetonephosphate (DHAP) to form Acyl-DHAP. The enzyme required for this step is Dihydroxyacetonephosphate Acyltransferase (DHAPAT). Step 2: Formation of the ester linkage by the replacing the fatty acid on the sn-1 position on the glycerol backbone with a long-chain fatty alcohol. Alkyl-DHAP is the resulting molecule. This step is catalysed by the enzyme Alkyl-DHAP Synthase (ADHAPS). Step 3: Reduction of Alkyl-DHAP to Alkyl-G3P. The enzyme Acyl/Alkyl Reductase is membrane bound so whilst at the same time catalysing the reaction, it also translocates the molecule to the cytosol. Step 4: Alkyl-G3P is shipped off to the endoplasmic reticulum where the biosynthesis process continues (Wanders and Waterman 2006). |
Image derived from Wanders and Waterman (2006)
The enzymes DHAPAT and ADHAPS have been known to form a heterodimer complex. in this form they are not active. they can only carry out their activity when in their monomeric forms (Brites et al 2004). They also exclusively live in the peroxisomes (Thai et al 2001).
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