Fig. 2.

Characterization of SPZJ as an efficient E2 signal peptide. a Alignment of SP23s from different CSFV strains. b Comparison between SP23s (SPZJ, SPC and SPHZ) in secretion of different E2s. E2 proteins were purified by Ni-NTA Agarose from equal volume of baculovirus culture prepared in the same method. E2 were detected in Western blotting with anti-E2 mAb 6D10. a. SPZJ is active for different E2 types. b. Comparison of SPs in induction of ZJE2. c. Comparison of SPZJ with other SPs in induction of their native E2s. c The production of E2 with SPZJ. The relative level of E2 was determined using E2ZJ induced with honeybee melittin signal peptide (HM) as base (1.0). The yield of secreting E2 with SPZJ was compared with other signal peptides, including SPC, SPHZ and HM. Experiments were performed in triplicate and data are shown as mean ± SD. Statistical significance is indicated as *(P < 0.05); **(P < 0.01); ***(P < 0.001)