Identification of a linear epitope on the fusion glycoprotein of respiratory syncytial virus.

The fusion glycoprotein of the Edinburgh strain of respiratory syncytial (RS) virus was cloned from infected cell mRNA. A full-length clone was subjected to sequence analysis, and compared with other strains of RS virus. The inferred primary amino acid sequence was used to generate a nested set of overlapping peptides spanning the mature protein. Peptides were synthesized on polyethylene pins and examined for their reactivity towards high titre human antisera. Decameric peptides spanning the highly conserved region between amino acids Lys and Ala (positions 470 to 490), reacted strongly with the sera and a detailed study with hexameric peptides located the epitope to FPSDEF, at positions 483 to 488. Replacement synthesis analysis revealed that Pro at position 484 and Glu at 487 were critical components of the binding site and could not be substituted.