Plasmalogenkopfgruppe

Plasmalogenkopfgruppe refers to the polar head group of plasmalogens, a subclass of glycerophospholipids characterized by a vinyl-ether linkage at the sn-1 position of the glycerol backbone. The head group is the phosphorylated moiety linked to the third carbon of glycerol and determines the lipid’s class and interactions with proteins and membranes. In plasmalogens, the head group is versatile and mirrors the diversity found in other phospholipids, typically forming derivatives such as phosphocholine, phosphoethanolamine, phosphoserine, or phosphoinositol.

The two major plasmalogen classes in mammalian tissues are plasmenylcholine (PlsCho) and plasmenylethanolamine (PlsEtn), corresponding to head groups of choline and ethanolamine, respectively. Smaller amounts of plasmenylserine (PlsSer) and plasmenylinositol (PlsPI) can also occur, depending on tissue type. The head group influences the molecule’s net charge, hydration, and interactions with membrane proteins, enzymes, and other lipids, thereby contributing to membrane curvature, microdomain formation, and signaling processes.

Biosynthesis and metabolism of plasmalogen head groups follow the broader phospholipid pathway, with initial formation of ether-linked backbones in peroxisomes and subsequent incorporation of the head group in the endoplasmic reticulum. The specific head group is added via CDP-activated donors (CDP-choline, CDP-ethanolamine, etc.). Alterations in plasmalogen levels or head-group composition are observed in various disorders and aging, making plasmalogen head groups an area of interest for biomarker research and functional studies in cell biology.