3.1 Antigenicity and hydrophilicity analyses of NTD of G1 and G2 PEDV S protein
Our and others’ previous researches have shown that G2 PEDV strains showed insertions and deletions in the S gene, especially in the NTD of the S gene, when compared with G1 PEDV strains. To analyze whether these insertions and deletions result in changes in antigenicity of S protein, comparative antigenicity and hydrophilicity analyses of NTD of G1 and G2 PEDV S protein were carried out. Comparison of antigenic index profiles of the NTD between G1 and G2 PEDV S protein strain indicated that two regions containing amino acid deletions/insertions/mutations exhibited higher degree of antigenic change. One region spans from aa 55 to 70/74, another spans from aa 114/118 to 163/166. Two new potential N-linked glycosylation sites (NST and NAT) were present in the S protein of G2 PEDV strains (Figure 1).