Host Antigen as the Sulphated Moiety of Influenza Virus Haemagglutinin

Abstract

Inorganic sulfate (35S) was incorporated into the hemagglutinin molecule of A/Memphis/1/71 (H3N2) influenza virus when a keratosulfate-like host antigen was also incorporated into the glycoproteins of virus grown in the chorioallantoic membrane of the embryonated hen''s egg. Little or no 35S-sulfate was incorporated when this host antigen was not present in the glycoproteins of virus grown in chick embryo kidney cells or in the chorioallantoic membrane of embryonated duck eggs. The presence of the keratosulfate-like host antigen was required for the stability of the hemagglutinin molecule in sodium dodecyl sulfate (SDS). The hemagglutinin molecules from virus grown in hens'' eggs were stable in SDS, but those from virus grown in duck eggs or chick embryo kidney cells were not and could not be isolated on cellulose acetate. Chemical analysis showed that there were 87 glucosamine residues and 3 molecules of sulfate/hemagglutinin subunit as calculated for a trimer molecule having a MW of 200,000. There was 1 sulfate molecule/HA1 polypeptide chain and this was associated with the slowest migrating carbohydrate-protein complex of an HA1 tryptic digest separated by polyacrylamide gel electrophoresis.