Plasmalogen

A typical plasmalogen based upon phosphatidyl ethanolamine with stearic acid at the second carbon and the characteristic vinyl at the first carbon at the top.

A plasmalogen is an ether lipid where the first position of glycerol binds a vinyl residue (from a vinyl alcohol) with the double bond next to the ether bond.

The second carbon has a typical ester-linked fatty acid, and the third carbon usually has a phospholipid head group like choline or ethanolamine.

Functions

In many tissues plasmalogens are minor constituents, but in heart tissue nearly 50% of phosphatidylcholine contains the alkenyl ether at carbon 1. Nervous tissues, testes and kidneys also contain significant amounts of plasmalogens.

Alkenyl ether-containing phospholipids can protect cells against the damaging effects of singlet oxygen, which at high concentrations can kill cells.

Plasmalogens also occur in invertebrates and single cell protozoans. Among bacteria they have been found in many anaerobic species including Clostridia, Megasphaera, and Veillonella.

History

Plasmalogens were first described when studying stained tissue sections.

These tissue sections were pre-treated with mercuric chloride that breaks the vinyl-ether bond and forms aldehydes that later react with a fuchsine-sulfurous acid stain, giving rise to coloured compounds inside the cytoplasm of the cells.

Pathology

Zellweger's syndrome is characterized by defects in peroxisome biogenesis resulting in the reduced production of plasmalogen synthesis.

See also

• Plasmalogen synthase

External links

• MeSH Plasmalogens

References