Figure 13.

Probing the conformational integrity of mammalian cell surface displayed HIV-1 native trimer using antibodies targeting important neutralization epitopes. gp120-gp41 trimer (PDB code 4NC0 (142)) is fit into the model of the cryo-EM density of the HIV-1 spike (gray mesh) (89). gp120 is multicolored, and gp41 is shown in red. As shown by checkmarks, antibodies targeting five major conformational epitopes: CD4bs (b12 and VRC01), V1/V2 loop (PG9, PG16, and PGT145), V3 loops (PGT128), gp120-gp41 interface (PGT151), and MPER region (2F5) bound various glycan-deficient gp160s and WT gp160 with comparable affinities indicating that native-like trimeric structure can be maintained in the absence of core gp120 glycans.