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Phosphatidylglycerol is a glycerophospholipid found in pulmonary surfactant. 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. The head group substituent glycerol is bonded through a phosphomonoester. It is the precursor of surfactant and its presence (>0.3) in the amniotic fluid of the newborn indicates fetal lung maturity. Approximately 98% of alveolar wall surface area is due to the presence of type I cells, with type II cells producing pulmonary surfactant covering around 2% of the alveolar walls. Once surfactant is secreted by the type II cells, it must be spread over the remaining type I cellular surface area. Phosphatidylglycerol is thought to be important in spreading of surfactant over the Type I cellular surface area. The major surfactant deficiency in premature infants relates to the lack of phosphatidylglycerol, even though it comprises less than 5% of pulmonary surfactant phospholipids. It is synthesized by head group exchange of a phosphatidylcholine enriched phospholipid using the enzyme phospholipase D. ==Biosynthesis== L-Glycerol-3-phosphate is activated by a CTP and pyrophosphate is cleaved off resulting in CDP-diglycerol. Glycerol-3-phosphate is attached to CDP-diglycerol and phosphatidylglycerol phosphate is formed, while CMP is released. The phosphate group is hydrolysed forming phosphatidylglycerol. Two phosphatidylglycerols form cardiolipin, the constituent molecule of the mitochondrial inner membrane. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「phosphatidylglycerol」の詳細全文を読む スポンサード リンク
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