7LX3

Cryo-EM structure of EDC-crosslinked ConSOSL.UFO.664 (ConS-EDC) in complex with bNAb PGT122

Summary for 7LX3

• Entry DOI: 10.2210/pdb7lx3/pdb
• EMDB information: 23565
• Descriptor: Env glycoprotein gp160, PGT122 Fab light chain, PGT122 Fab heavy chain, ... (8 entities in total)
• Functional Keywords: env, sosip, viral protein, viral protein-immune system complex, viral protein/immune system
• Biological source: Human immunodeficiency virus 1; More
• Total number of polymer chains: 9
• Total formula weight: 392794.42

Authors

Martin, G.M.,Ward, A.B.,Sattentau, Q.J. (deposition date: 2021-03-03, release date: 2022-03-09, Last modification date: 2024-11-13)

Primary citation

Martin, G.M.,Russell, R.A.,Mundsperger, P.,Harris, S.,Jovanoska, L.,Trajano, L.F.,Schiffner, T.,Fabian, K.,Tolazzi, M.,Scarlatti, G.,McFarlane, L.,Cheeseman, H.,Aldon, Y.,Schermer, E.E.,Breemen, M.,Sliepen, K.,Katinger, D.,Kunert, R.,Sanders, R.W.,Shattock, R.,Ward, A.B.,Sattentau, Q.J.
Profound structural conservation of chemically cross-linked HIV-1 envelope glycoprotein experimental vaccine antigens.
Npj Vaccines, 8:101-101, 2023

PubMed Abstract: Chemical cross-linking is used to stabilize protein structures with additional benefits of pathogen and toxin inactivation for vaccine use, but its use has been restricted by the potential for local or global structural distortion. This is of particular importance when the protein in question requires a high degree of structural conservation for inducing a biological outcome such as the elicitation of antibodies to conformationally sensitive epitopes. The HIV-1 envelope glycoprotein (Env) trimer is metastable and shifts between different conformational states, complicating its use as a vaccine antigen. Here we have used the hetero-bifunctional zero-length reagent 1-Ethyl-3-(3-Dimethylaminopropyl)-Carbodiimide (EDC) to cross-link two soluble Env trimers, selected well-folded trimer species using antibody affinity, and transferred this process to good manufacturing practice (GMP) for experimental medicine use. Cross-linking enhanced trimer stability to biophysical and enzyme attack. Cryo-EM analysis revealed that cross-linking retained the overall structure with root-mean-square deviations (RMSDs) between unmodified and cross-linked Env trimers of 0.4-0.5 Å. Despite this negligible distortion of global trimer structure, we identified individual inter-subunit, intra-subunit, and intra-protomer cross-links. Antigenicity and immunogenicity of the trimers were selectively modified by cross-linking, with cross-linked ConS retaining bnAb binding more consistently than ConM. Thus, the EDC cross-linking process improves trimer stability whilst maintaining protein folding, and is readily transferred to GMP, consistent with the more general use of this approach in protein-based vaccine design.

PubMed: 37443366
DOI: 10.1038/s41541-023-00696-w

Experimental method

ELECTRON MICROSCOPY (3.45 Å)