Properties of an acid phosphatase in pulmonary surfactant.
Lung surfactant, a lipid-protein complex purified from dog lungs, contains a highly active phosphomonoesterase associated with it. This phosphatase is quite specific for the hydrolysis of phosphatidic acid and 1-acyl-2-lysophosphatidic acid. The enzyme possesses many of the characteristics of the microsomal enzyme, phosphatidate phosphohydrolase (EC 3.1.3.4). In addition, we have shown that this enzyme will also convert phosphatidylglycerol phosphate [1-(3-sn-phosphatidyl)-sn-glycerol-1-P] to phosphatidylglycerol [1-(3-sn-phosphatidyl)-sn-glycerol] and Pi. The phosphatidylglycerol phosphate was made available to the surfactant enzyme in a coupled assay by hydrolysis of cardiolipin [1-(3-sn-phosphatidyl)-3-(3-sn-phosphatidyl)-sn-glycerol] by stereospecific cleavage with phospholipase C (phosphatidylcholine cholinephosphohydrolase, EC 3.1.4.3) from Bacillus cereus. This enzyme has been previously shown to generate the naturally occurring isomer of phosphatidylglycerol phosphate because it has specificity for the 3-(3-sn-phosphatidyl) group of cardiolipin. Other properties of the surfactant enzyme are discussed in relation to its presence in lung surface active material.
D000135:Acid Phosphatase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000818:Animals; D004285:Dogs; D005260:Female; D006863:Hydrogen-Ion Concentration; D008168:Lung / Q000201:enzymology*; D008297:Male; D010715:Phosphatidylglycerols / Q000378:metabolism*; D011663:Pulmonary Surfactants / Q000378:metabolism*; D013379:Substrate Specificity; D013439:Sulfhydryl Reagents / Q000494:pharmacology
D010715:Phosphatidylglycerols; D011663:Pulmonary Surfactants; D013439:Sulfhydryl Reagents; D000135:Acid Phosphatase