Engineering of single chain antibodies for solubility

Area of Science:

• Biotechnology
• Immunology
• Protein Engineering

Background:

• Bacterial expression systems are cost-effective for producing biologics.
• Achieving soluble antibody fragment production in bacteria remains a challenge.
• Single-chain variable fragments (scFvs) are crucial for antibody-based therapeutics.

Purpose of the Study:

• To introduce a novel method for designing intrinsically soluble single-chain variable fragments (scFvs).
• To enable straightforward production of scFvs in bacterial expression systems.
• To enhance the utility of scFvs in biopharmaceutical applications.

Main Methods:

• Grafting complementarity-determining region (CDR) loops onto intrinsically soluble subclass 3 framework regions (VH3 and VL3).
• Utilizing framework-donor sequences with specific hydrophobic core residues and desired CDR loops.
• Employing 3D modeling, mutation, and superposition to select optimal variable domains based on Root-Mean-Square Deviation (RMSD).

Main Results:

• The designed scFv was successfully produced in a soluble form in bacterial cells.
• The method facilitates the creation of stable and functional antibody fragments.
• Demonstrated feasibility of producing soluble scFvs through CDR grafting and computational modeling.

Conclusions:

• The presented method effectively designs intrinsically soluble scFvs for bacterial expression.
• This technique offers a viable strategy for simplified antibody fragment production.
• The findings contribute to advancing antibody engineering for therapeutic and diagnostic purposes.