Disulfide bonds in Sendai virus glycoproteins

The precursor of fusion protein (Fo) in Sendai virus growth in Vero cells can be cleaved by trypsin to forms F1 and F2, which can be resolved on SDS-polyacrylamide gels. However, if disulfide bonds are preserved during electrophoresis, F1 and F2 remain linked together even after trypsin treatment (F). Sendai virus growth in embryonated chicken eggs does not contain the precursor Fo. However, an F protein was found for Sendai virus grown in eggs when disulfide bonds were preserved during electrophoresis. The hemagglutinin-neuraminidase (HN) glycoproteins also appear to be disulfide-linked to form large complexes which are observed on SDS-polyacrylamide gels of nonreduced samples.