Expression studies of catalytic antibodies

Area of Science:

• Immunology
• Protein Engineering
• Biotechnology

Background:

• Antibody variable domains are crucial for antigen binding.
• Bacterial expression systems offer a scalable platform for protein production.
• Optimizing expression yields of functional antibody fragments is essential for research.

Purpose of the Study:

• To investigate the impact of human constant regions on the folding and bacterial expression of mouse immunoglobulin variable domains.
• To evaluate the utility of this system for generating in vivo expression libraries.
• To assess the applicability of this production system for antibody fragments.

Main Methods:

• Comparing expression yields of chimeric Fab fragments from hybridoma and myeloma sources in different fermentation conditions.
• Constructing and expressing novel heavy and light chain variable region combinations for in vivo expression libraries.
• Performing mutagenesis studies on recombinant catalytic Fab fragments to identify key residues affecting expression.

Main Results:

• Human constant regions positively influence the folding and bacterial expression of active, soluble mouse immunoglobulin variable domains.
• Significant differences in expression yields were observed for chimeric Fab fragments under various fermentation conditions.
• Mutagenesis revealed that single amino acid substitutions can drastically alter expression yields.

Conclusions:

• The described system facilitates the production of Fab fragments from catalytic and other hybridoma-derived antibodies.
• This approach is valuable for generating antibody fragments for crystallographic and structure-function analyses.
• The findings provide a foundation for improving recombinant antibody production in bacterial systems.