Figure 3.

Synthesis, Processing, and Incorporation of S Protein Variants into SARS-CoV-2 Virus-like Particles

(A) Schematic showing how SARS-CoV-2 structural proteins were produced in HEK293T cells and virus-like particles were enriched from the supernatant by ultracentrifugation.

(B) HEK293T cells were transfected with plasmids encoding the proteins indicated at the top. Total protein in cell lysates and in ultracentrifuge pellets from cell culture supernatant was normalized by Bradford assay, and then western blots were performed with the primary antibodies indicated on the left of the blots. Anti-Raptor antibody was used as a loading control for the cell lysate. Uncleaved S proteins, as well as the S1 and S2 cleavage products, are indicated on the right. Results here are representative of three independent rounds of transfection, ultracentrifugation, and westerns.