Rat alpha 1 macroglobulin inhibits hemagglutination by influenza C virus

Virus Res. 1985 Mar;2(2):183-92. doi: 10.1016/0168-1702(85)90248-5.


Purified alpha 1-macroglobulin (RMG) isolated from rat plasma was found to be a potent inhibitor of hemagglutination by influenza C virus. Neuraminidase treatment of purified RMG reduced its inhibitory activity by more than 80% indicating that sialic acid is required for maximal HI-activity. The inhibitory activity of RMG was shown to be sensitive to the receptor-destroying activity (RDA) of influenza C virus. Methylation analysis of the glycopeptides of RMG indicated the presence of only one major type of oligosaccharide which is a complex N-linked oligosaccharide with a biantennary structure. Comparison of the glycopeptides before and after neuraminidase treatment revealed that the oligosaccharides are terminated by sialic acid residues attached to galactose residues at position C-6. Methylation analysis was also performed on RMG which had lost its inhibitory activity upon incubation with RDA of influenza C virus. No difference between the glycopeptides of native and inactive RMG could be detected. Galactose was found to be substituted at position C-6 in both samples, indicating that also the oligosaccharides of inactive RMG are terminated by sialic acid. The implications of these results are discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antiviral Agents*
  • Chickens / immunology
  • Chromatography, Gel
  • Electrophoresis, Polyacrylamide Gel
  • Erythrocytes / immunology
  • Glycopeptides / analysis
  • Hemagglutination Inhibition Tests
  • Hemagglutination, Viral* / drug effects
  • Neuraminidase / pharmacology
  • Oligosaccharides / analysis
  • Orthomyxoviridae / immunology*
  • Rats
  • alpha-Macroglobulins / analysis
  • alpha-Macroglobulins / immunology*
  • alpha-Macroglobulins / isolation & purification


  • Antiviral Agents
  • Glycopeptides
  • Oligosaccharides
  • alpha-Macroglobulins
  • Neuraminidase