Phosphatidylglycerol (PG)

Phosphatidylglycerol (PG) is a ubiquitous glycerophospholipid that plays a vital role in the structural integrity and functionality of various biological membranes. In humans, it is a critical component of pulmonary surfactant, where it acts to stabilize the alveolar surface and prevent collapse during expiration; a deficiency in PG is a hallmark of neonatal respiratory distress syndrome (NIH, PubChem). Beyond the lungs, PG is the primary biosynthetic precursor to cardiolipin, a lipid essential for mitochondrial inner membrane function and aerobic respiration. In microbiology, PG is a major constituent of the plasma membranes of Gram-positive bacteria, making it a significant pharmacological target. The antibiotic daptomycin specifically targets PG to induce membrane perforation and bacterial cell death (PubMed). Clinically, PG levels are monitored in amniotic fluid to assess fetal lung maturity, and it is a key ingredient in exogenous surfactant replacement therapies used in neonatal intensive care (StatPearls).

Other names

PtdGly1,2-diacyl-sn-glycero-3-phospho-(1'-sn-glycerol)Glycerophosphoglycerol

Daptomycin binds to phosphatidylglycerol in the bacterial cell membrane in a calcium-dependent manner, leading to membrane depolarization and rapid cell death. In surfactant therapy, exogenous phosphatidylglycerol replaces deficient endogenous levels to lower surface tension in the alveoli.