In vitro sulfation of pulmonary surfactant-associated protein-35

Biochim Biophys Acta. 1987 Aug 5;914(2):205-11. doi: 10.1016/0167-4838(87)90065-3.


Surfactant-associated protein-35 consists of a group of phospholipid-associated proteins of 26-36 kDa isolated from pulmonary alveolar surfactant. In the rat, surfactant-associated protein-35 is synthesized from 26-kDa primary translation products which are cotranslationally acetylated and glycosylated to heterogeneous 30 and 34 kDa forms. High-mannose oligosaccharide-containing precursors of surfactant-associated protein-35 are processed in the rough endoplasmic reticulum and Golgi to complex-type oligosaccharides, resulting in a mature glycoprotein which exhibits extensive charge heterogeneity in two-dimensional isoelectric focusing SDS-polyacrylamide gel electrophoresis. Much of this charge heterogeneity is related to terminal sialylation of the two asparagine-linked oligosaccharides. In the present study, we report that surfactant-associated protein-35 is also sulfated. Sulfation of the 30 and 34 kDa forms of surfactant-associated protein-35 was clearly detected in primary cultures of rat Type II epithelial cells. These sulfated isoforms were sensitive to endoglycosidase F digestion, but resistant to neuraminidase, suggesting that sulfation occurred at oligosaccharide residues other than sialic acid. The lack of sulfation of the 26 kDa forms of surfactant-associated protein-35 and the resistance of the sulfated isoforms to endoglycosidase H digestion are consistent with Golgi-associated sulfation of the complex type oligosaccharides of surfactant-associated protein-35. Thus, sulfation is another component of the complex post-translational processing of surfactant-associated protein-35, which includes acetylation, hydroxylation, glycosylation, sialylation, sulfhydryl-dependent oligomerization and sulfation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cells, Cultured
  • Epithelium / metabolism
  • Glycoproteins / genetics*
  • Kinetics
  • Male
  • Molecular Weight
  • Protein Processing, Post-Translational
  • Proteolipids / biosynthesis
  • Proteolipids / genetics*
  • Proteolipids / isolation & purification
  • Pulmonary Alveoli / metabolism*
  • Pulmonary Surfactant-Associated Proteins
  • Pulmonary Surfactants / biosynthesis
  • Pulmonary Surfactants / genetics*
  • Pulmonary Surfactants / isolation & purification
  • Rats
  • Rats, Inbred Strains
  • Sulfates / metabolism
  • Sulfur Radioisotopes


  • Glycoproteins
  • Proteolipids
  • Pulmonary Surfactant-Associated Proteins
  • Pulmonary Surfactants
  • Sulfates
  • Sulfur Radioisotopes