Precision Modification of Native Antibodies.

Area of Science:

• Bioconjugation Chemistry
• Protein Engineering
• Immunology

Background:

• Antibodies, especially immunoglobulin G (IgG), are crucial affinity reagents in research, diagnostics, and therapy.
• Current antibody modification methods often yield heterogeneous conjugates due to labeling at lysine or cysteine residues.
• Homogeneous antibody conjugates prepared via bioorthogonal handles offer improved performance but require antibody engineering.

Purpose of the Study:

• To review recent strategies for site-specific labeling of native antibodies.
• To summarize the advantages and disadvantages of these novel conjugation techniques.
• To highlight methods that bypass chemical or enzymatic pre-treatments.

Main Methods:

• Site-specific introduction of bioorthogonal handles through enzymatic treatment, genetic code expansion, or genetically encoded tagging.
• Bioorthogonal conjugation reactions for functionalizing antibodies.
• Emerging strategies for direct site-specific labeling of native antibodies.

Main Results:

• Homogeneous antibody conjugates demonstrate superior performance in vitro and in vivo compared to heterogeneous ones.
• Engineered antibodies for bioorthogonal handle incorporation can impact folding, stability, yield, and cost.
• Recent advancements focus on labeling native antibodies without prior chemical or enzymatic modification.

Conclusions:

• Site-specific native antibody conjugation offers a promising alternative to traditional methods.
• These strategies aim to simplify conjugate preparation while maintaining or improving antibody function.
• Further research into native antibody labeling is essential for advancing antibody-based applications.