A synthetic peptide corresponding to the NH2 terminus of vesicular stomatitis virus glycoprotein is a pH-dependent hemolysin.

The spike protein of vesicular stomatitis virus, G protein, is a 68,000-Da glycoprotein which mediates viral binding, membrane fusion, and hemolysis. In an attempt to define the protein domain involved in membrane destabilization and fusion, a 25-amino acid peptide corresponding to the NH2 terminus of G protein was synthesized. We show here that this peptide is a pH-dependent hemolysin and that the pH and temperature optima for hemolysis by peptide and virus are similar. Antiserum prepared against this peptide is nonneutralizing and nonreactive with native G protein. Antipeptide antibodies, however, do react with sodium dodecyl sulfate-denatured protein, suggesting that the G protein NH2 terminus is "masked" in the native protein. The hemolytic activity of the synthetic peptide may reflect an analogous function of the NH2 terminus of G protein.