Crystal structure of a cocaine-binding antibody

Area of Science:

• Immunology
• Structural Biology
• Pharmacology

Background:

• Murine monoclonal antibody GNC92H2 targets free cocaine with high specificity.
• Improving antibody affinity and humanization is crucial for cocaine addiction immunopharmacotherapy and overdose treatment.

Purpose of the Study:

• Determine the crystal structure of a chimeric Fab fragment of GNC92H2 complexed with cocaine.
• Provide a structural basis for enhancing antibody affinity and humanization for therapeutic applications.

Main Methods:

• Crystallization of the engineered murine-human chimeric Fab of GNC92H2.
• X-ray diffraction to determine the complex structure at 2.3 Å resolution.
• Structural analysis of the cocaine-binding pocket.

Main Results:

• The crystal structure revealed a binding pocket with significant shape and charge complementarity to the cocaine framework.
• This complementarity explains the antibody's high specificity for cocaine over its metabolites.
• The structure provides a blueprint for rational antibody engineering.

Conclusions:

• The determined structure is foundational for mutagenesis strategies to increase binding affinity for cocaine and related derivatives.
• Further humanization of the antibody can be guided by this structural information.
• This work facilitates the development of advanced antibody-based therapeutics for cocaine use disorder and overdose.