Phosphatidylglycerol

Phosphatidylglycerol is a glycerophospholipid found in pulmonary surfactant[1] and in the plasma membrane where it directly activates lipid-gated ion channels.

The general structure of phosphatidylglycerol consists of a L-glycerol 3-phosphate backbone ester-bonded to either saturated or unsaturated fatty acids on carbons 1 and 2.

Phosphatidylglycerol is thought to be important in spreading of surfactant over the Type I cellular surface area.

It is synthesized by head group exchange of a phosphatidylcholine enriched phospholipid using the enzyme phospholipase D. Phosphatidylglycerol (PG) is formed via a complex sequential pathway whereby phosphatidic acid (PA) is first converted to CDP-diacylglyceride by the enzyme CDP-diacylglyceride synthase.

[4] In bacteria, another membrane phospholipid known as cardiolipin can be synthesized by condensing two molecules of phosphatidylglycerol; a reaction catalyzed by the enzyme cardiolipin-synthase.