Nanoparticle orientationally displayed antigen epitopes improve neutralizing antibody level in a model of porcine circovirus type 2

Ding, Peiyang; Zhang, Teng; Li, Yafei; Teng, Man; Sun, Yaning; Liu, Xiao; Chai, Shujun; Zhou, Enmin; Jin, Qianyue; Zhang, Gaiping

where M Cap is the mass of Cap protein conjugated to AuNPs, which is 6.06 μg; Mr Cap is the relative molecular mass of Cap protein, which is 25.76 kDa; M Au is 50 μg in 1 mL solution, ρ Au is the density of gold, which is 19.3 g/mL; and d is the diameter of the AuNPs, which is 23 nm. The number of AuNPs was calculated under the assumption that all gold chloride trihydrate reacted completely and that all resulting nanoparticles were of uniform size. All parameters use international systems of unit symbol. After calculation, the number of Cap protein molecule was 1.42×10 14 and the total number of AuNPs in the 1 mL solution was found to be 3.96×10 11 . Based on this, we approximated that 358 molecules of Cap protein were conjugated on each AuNP, which is approximately six times the amount of Cap protein on PCV2 (60). 26 Interestingly, the surface area of Cap-AuNP conjugates was about 6-fold to PCV2, whose diameter is about 17 nm, while the mean diameter of Cap-AuNPs is 42 nm. This indicated that Cap protein was closely distributed on the surface of AuNPs, with likely no voids. We hypothesized