FIG. 1.

Construction of the subtype C envelope immunogens. (A) Amino acid sequences of full-length and modified subtype C envelope immunogens. ΔV2 and ΔV1V2 have 32- and 76-amino-acid deletions, respectively, compared to the full-length sequence. The larger ΔV1V2 deletion removes seven additional potential N-linked glycosylation sites. GAG amino acid sequences were inserted into the deleted sites. (B) Diagram of gp140 and gp160. gp140 is a secreted form. The gene sequence, including the signal leader, was sequence modified. The cleavage site mutation was introduced for production of the oligomeric gp140 protein immunogens.