Isolation and Characterization of Two Glyeoproteins from Patients with Alveolar Proteinosis

Our plain-English summary of Isolation and Characterization of Two Glyeoproteins from Patients with Alveolar Proteinosis, by M.A. Passero, R.W. Tye, K.H. Kilburn (1978).

The study

• Authors: M.A. Passero, R.W. Tye, K.H. Kilburn
• Published: Proceedings of the National Academy of Sciences 70(4):973-976, April. (1978)
• Type of article: Journal article
• Our copy: from Johns-Manville's own medical library. The article is still under copyright, so we describe it here rather than post it.

In plain English

This was a laboratory study of lung-washing (lavage) material from patients with alveolar proteinosis, a chronic lung disease in which the air sacs fill with an amorphous material. It did not study asbestos or any other exposure. The patients underwent therapeutic lavage with saline, and the authors analysed the material that would not dissolve in salt solution. This insoluble sediment from all four patients contained the same three main protein bands, with molecular weights of 69,000, 62,000 and 36,000. The authors identified the 69,000 protein as albumin, based on its amino-acid composition and its reaction with antiserum to human serum albumin. The 62,000 protein could not be fully separated from it and had about 10% albumin contamination. The 36,000 protein contained sugars, including sialic acid, mannose, galactose, fucose and glucose. The authors judged that the 62,000 and 36,000 glycoproteins were probably not serum glycoproteins. They suggested these proteins might be basal-lamina (supporting-membrane) proteins that are overproduced or not properly used, but noted other evidence against this. They also raised the possibility that the proteins came from alveolar cell membranes.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Laboratory biochemical study (protein isolation and characterization) of lung lavage material
• Who was studied: Lung lavage material from 4 patients with alveolar proteinosis who underwent therapeutic saline lavage (1 patient under Dr. Ramirez-R., 3 under Dr. J. Kylstra)
• Exposure: None. The study does not concern asbestos or any occupational exposure. The material analysed was saline lung-lavage material.
• Main results:
  • The salt-insoluble lavage sediment from all 4 patients contained the same three major peptides
  • The authors identified the 69,000 peptide as albumin. Its amino-acid composition was similar to that reported for human albumin, and it formed a precipitin band with antiserum to human serum albumin.
  • The 62,000 peptide could not be completely separated from the 69,000 peptide. Gel electrophoresis showed about 10% contamination by serum albumin.
  • The 36,000 peptide contained sialic acid, mannose, galactose, fucose, glucose and amino sugars
  • 4-Hydroxyproline was present in the glycoproteins
  • The lavage supernatant (the fluid portion) showed one major band on gel electrophoresis, with molecular weight 69,000
• The authors' conclusion: The authors concluded that the 62,000 and 36,000 glycoproteins were similar in amino-acid composition and probably not serum glycoproteins. They proposed that these might be lung basal-laminar proteins that are overproduced or not properly used, or proteins from alveolar cell membranes, while noting evidence against the basal-lamina idea.
• Limitations the authors state:
  • The 62,000 peptide could not be fully purified away from the albumin-like 69,000 peptide
  • The authors noted other observations suggesting the two glycoproteins may not come from basal lamina

Topics

Medical terms in this study, explained in our Lexicon: Glycoprotein.

Browse return to medical research.