Porcine circovirus 2(PCV2)causes significant economic losses in the swine industry worldwide.Vaccination is a major defense against PCV2 dissemination and its associated diseases.Better understanding of PCV2 assembly and its entry into cells will improve PCV2 vaccines and may foster the novel use of PCV2 VLPs as a drug carrier.Through the sequence alignment,protein 3D-structure homology modeling and mutation analysis,Key amino acid residues within it have been determined.In this study,Loop BC on the structure of Capsid has analyzed and predicted by 3D simulation,the conserved and divergent amino acid residues within the loop are then determined.The production and in vitro assembly of mutant proteins,combined with multiple technologies including electron microscopy,constructed infectious DNA clone and fast protein liquid chromatography(FPLC)will be employed to explore the mechanism of PCV2 VLPs assembly and invasion of virus particles.The resultant findings will constitute a basis for the research and development of PCV2 vaccine and drug delivery. |