Binding of mAb 1A9 to wild-type, mutant D1128A, mutant N1056K and mutant D1128A/N1056K S proteins by Western Blot and immunoprecipitation.

<p>293(mock) or with plasmids expressing full length wild-type S (S-WT) or full length mutant S (S-D1128A, S-N1056K and S-D1128A/N1056K). (A) Western Blot analysis was performed on the cell lysates using mAb 1A9 to determine if it can bind to the different S proteins. MAb 7G12, which binds to the S1 of the S protein, was used as a control antibody to detect protein expression. (B) Cell lysates containing S-WT, S-D1128A, S-N1056K or S-D1128A/N1056K were subjected to immunoprecipitation (IP) using mAb 1A9 or 7G12 and protein A beads. S proteins immunoprecipitated by mAbs 1A9 and 7G12 were detected using rabbit anti-SΔ1 antibody in Western blot analysis (WB). The rabbit anti-SΔ1 antibody binds to amino acids 48–358 of the S1 subunit.