Phospholipids are crucial components of the cell membrane bilayers. Most of these phospholipids are composed of a diglyceride (diacylglycerol) moiety, a phosphate group and a simple organic molecule such as choline, serine or ethanolamine. The anionic phosphate groups and polar groups such as choline form the hydrophilic heads and the fatty acid chains in diacylglycerol form the hydrophobic tails in the membrane bilayer. A phospholipid with choline as simple organic molecule is phosphatidylcholine and it is also known as lecithin.
The apicomplexan parasites, Plasmodium falciparum and Toxoplasma gondii can de novo synthesise phospholipids such as phosphatidylcholine and phosphatidylethanolamine from choline and ethanolamine respectively [1, 2]. The analysis of the Cryptosporidium genomes showed that they can also de novo synthesise phosphatidylcholine from choline. They also possess the enzymes which catalyse the metabolism of the phospholipids. In contrast to T. gondii phosphatidylcholine metabolism pathway, Cryptosporidium species do not possess the abilities to synthesise choline phosphate from O-phosphoethanolamine and betaine from choline.
|Enzyme||EC Number||Gene id|
|Diacylglycerol choline phosphotransferase||18.104.22.168||Chro.40053|
|Diacylglycerol choline phosphotransferase||22.214.171.124||Chro.40314|
Sources and fates of metabolites
|Substrate||Source pathways||Product||Fate pathways|
|Choline||Host||Phosphatidylcholine||Phosphatidylethanolamine and phosphatidylserine metabolism|
|S-adenosylmethionine||Methionine metabolism||S-adenosylhomocysteine||Methionine metabolism|
|1,2-Diacylglycerol||Phosphatidylethanolamine and phosphatidylserine metabolism, Inositol phosphate metabolism||sn-glycerol-3P||Phosphatidylethanolamine and phosphatidylserine metabolism|