8TJT

The Fab fragment of an anti-glucagon receptor (GCGR) antibody

Summary for 8TJT

• Entry DOI: 10.2210/pdb8tjt/pdb
• Descriptor: anti-GCGR Fab light chain, anti-GCGR Fab heavy chain (3 entities in total)
• Functional Keywords: antibody, glucagon receptor, fab fragment, immune system
• Biological source: Homo sapiens; More
• Total number of polymer chains: 8
• Total formula weight: 190723.88

Authors

Dai, J.,Carter, P.J.,Sudhamsu, J.,Kung, J. (deposition date: 2023-07-24, release date: 2024-02-14, Last modification date: 2024-10-23)

Primary citation

Dai, J.,Izadi, S.,Zarzar, J.,Wu, P.,Oh, A.,Carter, P.J.
Variable domain mutational analysis to probe the molecular mechanisms of high viscosity of an IgG 1 antibody.
Mabs, 16:2304282-2304282, 2024

PubMed Abstract: Subcutaneous injection is the preferred route of administration for many antibody therapeutics for reasons that include its speed and convenience. However, the small volume limit (typically 2 mL) for subcutaneous delivery often necessitates antibody formulations at high concentrations (commonly ≥100 mg/mL), which may lead to physicochemical problems. For example, antibodies with large hydrophobic or charged patches can be prone to self-interaction giving rise to high viscosity. Here, we combined X-ray crystallography with computational modeling to predict regions of an anti-glucagon receptor (GCGR) IgG antibody prone to self-interaction. An extensive mutational analysis was undertaken of the complementarity-determining region residues residing in hydrophobic surface patches predicted by spatial aggregation propensity, in conjunction with residue-level solvent accessibility, averaged over conformational ensembles from molecular dynamics simulations. Dynamic light scattering (DLS) was used as a medium throughput screen for self-interaction of ~ 200 anti-GCGR IgG variants. A negative correlation was found between the viscosity determined at high concentration (180 mg/mL) and the DLS interaction parameter measured at low concentration (2-10 mg/mL). Additionally, anti-GCGR variants were readily identified with reduced viscosity and antigen-binding affinity within a few fold of the parent antibody, with no identified impact on overall developability. The methods described here may be useful in the optimization of other antibodies to facilitate their therapeutic administration at high concentration.

PubMed: 38269489
DOI: 10.1080/19420862.2024.2304282

Experimental method

X-RAY DIFFRACTION (2.7 Å)