title: Rat alpha 1 macroglobulin inhibits hemagglutination by influenza C virus.
abstract: 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.
authors.forename: G
authors.initials: G
authors.lastname: Herrler
authors.forename: R
authors.initials: R
authors.lastname: Geyer
authors.forename: H P
authors.initials: HP
authors.lastname: Müller
authors.forename: S
authors.initials: S
authors.lastname: Stirm
authors.forename: H D
authors.initials: HD
authors.lastname: Klenk
mesh_terms: D000818:Animals; D000998:Antiviral Agents; D002645:Chickens / Q000276:immunology; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000276:immunology; D006020:Glycopeptides / Q000032:analysis; D006385:Hemagglutination Inhibition Tests; D006387:Hemagglutination, Viral / Q000187:drug effects; D009439:Neuraminidase / Q000494:pharmacology; D009844:Oligosaccharides / Q000032:analysis; D009975:Orthomyxoviridae / Q000276:immunology*; D051381:Rats; D000511:alpha-Macroglobulins / Q000032:analysis / Q000276:immunology* / Q000302:isolation & purification
chemical_list: D000998:Antiviral Agents; D006020:Glycopeptides; D009844:Oligosaccharides; D000511:alpha-Macroglobulins; D009439:Neuraminidase