[Biological consequences of breaks and reunions of disulfide bonds in influenza virus proteins].

Consequences of chemical breakage of native disulphide bonds in influenza virus neuraminidase and hemagglutinin glycoproteins induced by mercaptoethanol treatment were studied. Under conditions of blocked reoxidation of thiol groups, this treatment led to significant inhibition of hemagglutinating activity and infectivity of virus particles, and to a lesser inhibition of neuraminidase activity, as well as to promotion of endogenous proteolytic activity. Analysis of virus particles proteins by polyacrylamide gel electrophoresis indicated association of these biological effects with breakage of disulphide bridges, mainly in hemagglutinin glycoproteins. Under certain conditions, the proteins were capable of reformation of disulphide bridges as manifested in restoration of virion biological activity and electrophoretic characteristics of proteins.