9VCA

Binding site between C-reactive protein and c2cc monoclonal antibody

Summary for 9VCA

• Entry DOI: 10.2210/pdb9vca/pdb
• EMDB information: 64950
• Descriptor: C-reactive protein, Monoclonal IgG antibody heavy chain fragment, Monoclonal IgG antibody light chain fragment (3 entities in total)
• Functional Keywords: c-reactive protein, crp, monoclonal antibody, immune complex, igg, immune system
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 3
• Total formula weight: 96103.58

Authors

Moiseenko, A.V.,Kalikin, A.V. (deposition date: 2025-06-05, release date: 2025-11-19)

Primary citation

Moiseenko, A.V.,Kalikin, A.V.,Orekhov, P.S.,Byzova, N.A.,Zherdev, A.V.,Shaitan, K.V.,Dzantiev, B.B.,Sokolova, O.S.
Cryo-EM structure of pentameric C-reactive protein in complex with monoclonal IgG antibodies.
Febs J., 2025

PubMed Abstract: C-reactive protein (CRP) plays a central role in innate immunity and serves as a key biomarker of inflammation. Despite its clinical importance, the structural basis of CRP interactions with antibodies remains poorly characterized. Using cryo-electron microscopy (cryo-EM), we resolved the structure of immune complexes formed between pentameric CRP and monoclonal immunoglobulin G (IgG) antibodies at up to 2.4 Å resolution. The complexes display a barrel-shaped architecture, with two CRP pentamers bridged by three to five antibodies. We built an atomic model of the CRP-antibody interface, identifying a binding site on the A-face of CRP mediated exclusively by hydrogen bonds, without salt-bridge formation. These findings provide structural insights into CRP-IgG recognition and offer a basis for the rational design of improved antibodies.

PubMed: 41159871
DOI: 10.1111/febs.70310

Experimental method

ELECTRON MICROSCOPY (2.4 Å)