The phosphohydrolase activity in lamellar bodies and its relationship to phosphatidylglycerol and lung surfactant formation.

Phosphohydrolase activity of a lamellar body-enriched preparation from pig lung was examined to ascertain if two separate enzymes catalyze the hydrolysis of phosphatidic acid and phosphatidylglycerol 3-phosphate. From sulfhydryl inhibition, heat inactivation and substrate specificity studies, we suggest that one phosphohydrolase may account for the hydrolysis of both substrates. The relationship of the reported experiments to the biosynthesis of the glycerophospholipids present in surfactant is discussed.