9J66
Cryo-EM structure of the SARS-CoV-2 S 6P trimer in complex with the human neutralizing antibody Fab fragment CAV-C65 (local refinement)
Summary for 9J66
| Entry DOI | 10.2210/pdb9j66/pdb |
| EMDB information | 61167 |
| Descriptor | CAV-C65 Heavy chain, CAV-C65 Light chain, Spike protein S1 (3 entities in total) |
| Functional Keywords | sars-cov-2, spike glycoprotein, neutralizing antibody, viral protein-immune system complex (local refinement), viral protein |
| Biological source | Homo sapiens More |
| Total number of polymer chains | 4 |
| Total formula weight | 91388.17 |
| Authors | |
| Primary citation | Xu, M.,Zhang, Z.,Sun, Y.,Mai, H.,Liu, S.,Liu, S.,Lv, K.,Yu, F.,Wang, Y.,Yue, X.,Zhang, J.,Cai, X.,Zhao, R.,Lu, H.,Liu, L.,Luo, H.,Zhao, H.,Wang, Y.,Gong, P.,Chen, S.,Jing, X.,Zhao, J.,Chen, Y.Q. IgA class switching enhances neutralizing potency against SARS-CoV-2 by increased antibody hinge flexibility. Antiviral Res., 235:106082-106082, 2025 Cited by PubMed Abstract: IgA antibodies are critical components of the mucosal immune barrier, providing essential first-line defense against viral infections. In this study, we investigated the impact of antibody class switching on neutralization efficacy by engineering recombinant antibodies of different isotypes (IgA1, IgG1) with identical variable regions from SARS-CoV-2 convalescent patients. A potent, broad-spectrum neutralizing monoclonal antibody CAV-C65 exhibited a ten-fold increase in neutralization potency upon switching from IgG1 to IgA1 monomer. Structural analysis revealed that this antibody binds to two adjacent receptor binding domains on the spike protein. Enhanced neutralization by IgA1 was attributed to the combined effects of increased affinity, unique hinge region properties, and potential cross-linking of viral particles. Inhaled CAV-C65 IgA1 demonstrated prophylactic efficacy against lethal SARS-CoV-2 infection in hACE2 mice. These findings highlight the pivotal role of IgA in antiviral immunity and inform the development of IgA-based therapeutics. PubMed: 39828085DOI: 10.1016/j.antiviral.2025.106082 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (3.55 Å) |
Structure validation
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