Hydrophobic proteins of lamellated osmiophilic bodies isolated from pig lung

Abstract

In addition to proteins insoluble in organic solvents, lamellated bodies isolated from pig lung and surfactant prepared from bronchopulmonary lavage fluid contain another group of proteins that are extracted together with lipid into the organic phase. These hydrophobic proteins constitute about 40% of the total protein of lamellated bodies and about 13% of the total protein of surfactant isolated from lavage fluid; less than 1% of the total protein of pig lung microsomal fraction and mitochondria is extracted by organic solvents. The hydrophobic proteins of lamellated bodies were separated into 4 fractions and freed from phospholipid by chromatographic procedures. Their apparent MW vary between 11,500 and 16,500; they contain 72-79% of hydrophobic residues and 16-22% of sulfur-containing amino-acids; leucine is the major N-terminal amino acid in each case.