Fig. 2From: Optimization of Zika virus envelope protein production for ELISA and correlation of antibody titers with virus neutralization in Mexican patients from an arbovirus endemic regionCharacterisation of ZIKV Env proteins. a. Silver stained PAGE gel showing purity of ZIKV Env proteins: commercial Env based on African Strain (left panel), Env-CD4 (middle) and Env (right) based on Asian-lineage strain. Three concentrations of Env proteins were used: 500 ng, 250 ng and 125 ng for African ZIKV Env (commercial) and Asian-lineage ZIKV Env-CD4. Env-CD4 showed three distinctive bands at ~ 65 kDa, ~ 45 kDa and ~ 25 kDa on the gel, corresponding to Env-CD4, Env and CD4 fusion tag (CD4), respectively. CD4 fragment is liberated following cleavage from Env-CD4 protein into Env and CD4. b. Western blot of the purified ZIKV Env-CD4 and Env proteins using a pan-flavivirus antibody, sera from ChAdOx1 ZIKV prME_ΔTM immunized mice and Zika Env monoclonal antibody. For Env-CD4, the top band corresponds to Env-CD4 protein and the bottom band to Env protein which may be formed following cleavage from Env-CD4. c. Western blot of the purified Env-CD4 using an anti-His antibody (1:2000). For Env-CD4, the top band is Env-CD4 protein and bottom band corresponds to CD4 (His). An unrelated malaria protein (cCSP-His) was used as positive control for the His antibody and as a negative control for the ZIKV-Env specific antibodies. Negative control is cell-free mediaBack to article page