Prediction and verification of the linear B-cell epitopes of staphylococcal enterotoxin G protein

In order to locate the B-cell linear epitopes of SEG protein,epitope prediction was performed using the amino acid sequence of SEG protein from Staphylococcus aureus standard strain ATCC25923.The secondary structure,flexible regions,hydrophilicity,surface accessibility and antigenic index of the protein were analyzed using the DNAStar Protean program,and five potential epitopes were screened,which were located at amino acid positions 24 to 31,37 to 46,80 to 84,120 to 127 and 141 to 149.Among them,the epitopes at amino acid positions 37 to 46,120 to 127 and 141 to 149 were entirely exposed on the surface of the 3D structure model of SEG protein.To verify the prediction,three potential epitope peptides exposed on the surface of the 3D structure were artificially synthesized and detected by peptide-ELISA.The results showed that the three potential epitopes exposed on the surface of the 3D structure had a specific binding to purified antibodies against SEG protein.They were indeed B-cell linear epitopes of the SEG protein.