7RYU

Anti-HIV neutralizing antibody Ab1303 Fab isolated from sequentially immunized mcaques

Summary for 7RYU

• Entry DOI: 10.2210/pdb7ryu/pdb
• Descriptor: Ab1303 Fab heavy chain, Ab1303 Fab light chain (3 entities in total)
• Functional Keywords: anti-hiv neutralizing antibody; antibody fab;, immune system
• Biological source: Macaca mulatta (Rhesus monkey); More
• Total number of polymer chains: 2
• Total formula weight: 48758.15

Authors

Yang, Z.,Bjorkman, P.J. (deposition date: 2021-08-26, release date: 2022-01-19, Last modification date: 2024-11-20)

Primary citation

Yang, Z.,Dam, K.A.,Bridges, M.D.,Hoffmann, M.A.G.,DeLaitsch, A.T.,Gristick, H.B.,Escolano, A.,Gautam, R.,Martin, M.A.,Nussenzweig, M.C.,Hubbell, W.L.,Bjorkman, P.J.
Neutralizing antibodies induced in immunized macaques recognize the CD4-binding site on an occluded-open HIV-1 envelope trimer.
Nat Commun, 13:732-732, 2022

PubMed Abstract: Broadly-neutralizing antibodies (bNAbs) against HIV-1 Env can protect from infection. We characterize Ab1303 and Ab1573, heterologously-neutralizing CD4-binding site (CD4bs) antibodies, isolated from sequentially-immunized macaques. Ab1303/Ab1573 binding is observed only when Env trimers are not constrained in the closed, prefusion conformation. Fab-Env cryo-EM structures show that both antibodies recognize the CD4bs on Env trimer with an 'occluded-open' conformation between closed, as targeted by bNAbs, and fully-open, as recognized by CD4. The occluded-open Env trimer conformation includes outwardly-rotated gp120 subunits, but unlike CD4-bound Envs, does not exhibit V1V2 displacement, 4-stranded gp120 bridging sheet, or co-receptor binding site exposure. Inter-protomer distances within trimers measured by double electron-electron resonance spectroscopy suggest an equilibrium between occluded-open and closed Env conformations, consistent with Ab1303/Ab1573 binding stabilizing an existing conformation. Studies of Ab1303/Ab1573 demonstrate that CD4bs neutralizing antibodies that bind open Env trimers can be raised by immunization, thereby informing immunogen design and antibody therapeutic efforts.

PubMed: 35136084
DOI: 10.1038/s41467-022-28424-3

Experimental method

X-RAY DIFFRACTION (1.51 Å)