Bovine pulmonary surfactant: chemical composition and physical properties.
Bovine pulmonary surfactant was obtained by endotracheal lavage of lungs from newly slaughtered cows followed by differential centrifugation. Lipid extracts of bovine surfactant contained 3% neutral lipid, mainly as cholesterol and diacylglycerol and 97% phospholipid. Phosphatidylcholine (79%) and phosphatidylglycerol (11%) accounted for most of the phospholipids with smaller amounts of phosphatidylethanolamine, phosphatidylinositol, lyso-bis-phosphatidic acid and sphingomyelin. Fatty acid analysis revealed high levels of palmitate in phosphatidylcholine and to a lesser extent phosphatidylglycerol, but not in the other diacylphospholipids. Phosphatidylcholine was 53% disaturated and phosphatidylglycerol was 23% disaturated. Monoenoic species accounted for the major proportion of the remaining lipid. The protein content was 10% as estimated by the Lowry procedure and 5% when determined by amino acid analysis. Extraction with chloroform/methanol removed ca. 90% of the protein but had no effect on the surfactant properties as evaluated by a pulsating bubble technique.
D000818:Animals; D002417:Cattle / Q000378:metabolism*; D002784:Cholesterol / Q000032:analysis; D005989:Glycerides / Q000032:analysis; D008055:Lipids / Q000032:analysis*; D010743:Phospholipids / Q000032:analysis; D011506:Proteins / Q000032:analysis; D011663:Pulmonary Surfactants / Q000032:analysis* / Q000302:isolation & purification; D013499:Surface Properties
D005989:Glycerides; D008055:Lipids; D010743:Phospholipids; D011506:Proteins; D011663:Pulmonary Surfactants; D002784:Cholesterol