羊口疮病毒单克隆抗体2A3可变区鉴定及其建模分析OA

Orf,caused by Orf virus(ORFV),is an acute and highly contagious zoonotic disease that is prevalent in pastoral areas worldwide,posing long-term threat to the development of local animal husbandry.Currently,highly effective and practical diagnostic and therapeutic agents against Orf are scarce.In our previous study,the anti-ORFV-B2L monoclonal antibody 2A3 was prepared,but the amino acid compositions of its heavy chain variable region(VH),light chain variable region(VL),and complementarity determining regions(CDRs)remained unknown,which hindered the applied research of 2A3 and the design of its single-chain antibody.In this study,the VH and VL gene sequences of 2A3 were successfully obtained through RT-PCR.The amino acid composition of the variable regions and CDRs was analyzed and determined using IgBLAST and the VBASE2 database,and their spatial structure was presented through homology modeling.The results showed that the VH gene is 342 bp in length,belonging to the IgG1 subtype,and the VL gene is 336 bp in length,belonging to the Kappa type.Compared with the 2E4 monoclonal antibody,its variable regions and CDRs have unique characteristics.Modeling results indicated that the VH and VL of the 2A3 antibody and their CDRs form a complete and stable"pocket"spatial conformation.This study lays the foundation for exploring the molecular mechanism of 2A3's specific binding to ORFV-B2L and for developing single-chain antibodies against ORFV.