Trimeric HIV-1-Env Structures Define Glycan Shields from Clades A, B, and G

“…However, M1-g234 is also an essential epitope for that antibody, which may compensate for the lower number of interacting glycans with g276. These results are consistent with previous suggestions 6 that crowding of glycans would potentially allow for additional glycan-antibody interactions, that may lead to an increased probability of generating bNAbs.…”

“…This was paradoxical, considering the similar enhancing effects of kifunensine, GNT1- and 2FF (Figs 2A and 3 ). On the other hand, the slight loss of sensitivity with NA treatment is consistent with previous reports that 35O22 recognizes complex glycans (N88, N241 and N625 in the JR-FL strain) [ 4 , 21 , 23 ]. Later, we address the unexpected effects of late modifications on PGT151 and 35O22 sensitivities.…”

“…Analysis of this structure highlights distinct sets of interactions observed between the light chains of VRC01 GL or VRC01 MAT and glycan Asn276, which is rotated ~90˚ when comparing the two structures ( Figure 3C–D ). In line with our previous observation that Asn276 is important for VRC01 GL recognition ( McGuire et al, 2016 ), we observed that Asn276 is hydrogen bonded to the VRC01 GL light chain residue Tyr91 in our 426c core † -VRC01 GL and 426c DS-SOSIP D3 † -VRC01 GL structures, but not in the JR-FL SOSIP-VRC01 MAT crosslinked complex structure ( Figure 3C–E ) (PDB: 5FYK) ( Stewart-Jones et al, 2016 ). The CDRL1 of VRC01 GL has been shown to adopt multiple conformations both when unliganded and when bound to eOD-GT6; the latter of which lacked a glycan at position Asn276 ( Jardine et al, 2013 ).…”