9G6Q image
Entry Detail
PDB ID:
9G6Q
Keywords:
Title:
scFv IP11 in complex with rocuronium
Biological Source:
Source Organism:
PDB Version:
Deposition Date:
2024-07-19
Release Date:
2025-02-12
Method Details:
Experimental Method:
Resolution:
1.20 Å
R-Value Free:
0.18
R-Value Work:
0.16
R-Value Observed:
0.16
Space Group:
P 21 21 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:scFv-IP11
Chain IDs:A (auth: H)
Chain Length:121
Number of Molecules:1
Biological Source:Mus musculus
Polymer Type:polypeptide(L)
Description:scFv-IP11
Chain IDs:B (auth: L)
Chain Length:132
Number of Molecules:1
Biological Source:Mus musculus
Ligand Molecules
Primary Citation
Antibody-secreting cell repertoires hold high-affinity anti-rocuronium specificities that can induce anaphylaxis in vivo.
J.Allergy Clin.Immunol. 155 1557 1574 (2025)
PMID: 39892658 DOI: 10.1016/j.jaci.2025.01.025

Abstact

BACKGROUND Neuromuscular blocking agents (NMBA) are muscle relaxants used to assist mechanical ventilation but lead in 1/10,000 anesthesia to severe acute hypersensitivity reactions i.e., anaphylaxis. Incidences vary between types of NMBAs. Rocuronium, a widely used non-depolarizing aminosteroid NMBA, induces among the highest anaphylaxis rates. Rocuronium-induced anaphylaxis is proposed to rely on pre-existing rocuronium-binding antibodies, but no such antibodies have ever been identified. OBJECTIVES Identify rocuronium-specific antibody repertoires from plasma cells or plasmablasts of rocuronium-immunized mice, and determine the affinities, structures and anaphylactogenic potential of these antibodies for rocuronium. METHODS Herein, we engrafted rocuronium onto carrier proteins allowing immunization of mice against rocuronium, screening for rocuronium-specific antibody responses, and sorting of rocuronium-specific plasma cells using droplet microfluidics coupled to single-cell antibody gene (VH and VL) sequencing. RESULTS The two different repertoires of >500 VH-VL pairs were oligoclonal, comprised of three major clonal families, and displayed convergence. Expressed as human IgG1, these antibodies demonstrated subnanomolar affinities for rocuronium with families either monospecific for rocuronium or cross-reactive only for closely-related NMBAs. Expressed as human IgE, they triggered human mast cell and basophil activation, and severe passive systemic anaphylaxis in mice humanized for the IgE receptor FcεRI. Co-crystal structures between rocuronium and antibody representatives of three different VH-VL families revealed distinct interaction modes with, however, the ammonium group involved systematically in the binding interface. CONCLUSIONS This work identifies the epitopes of antibody reactivity to rocuronium, demonstrates anaphylactogenic potential of anti-rocuronium IgE and establishes the first mouse model of NMBA anaphylaxis.

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