Fluorescent IgG fusion proteins made in E. coli

Area of Science:

• Biotechnology
• Molecular Biology
• Immunology

Background:

• Immunoglobulin G (IgG) antibodies are crucial research tools and biopharmaceuticals.
• Current production methods for therapeutic IgGs are expensive, while diagnostic antibodies often rely on animal sources.
• Existing E. coli expression systems (Inclonals) can produce full-length IgGs and fusion proteins.

Purpose of the Study:

• To investigate the feasibility of using the Inclonals technology to create fluorescent IgG fusion proteins.
• To assess the functionality and fluorescence properties of IgGs fused with different fluorescent proteins.

Main Methods:

• Utilized the Inclonals technology for expressing full-length IgG fused to fluorescent proteins in E. coli.
• Evaluated antigen-binding functionality and fluorescence intensity of the fusion proteins after refolding.
• Tested tandem fusions of multiple fluorescent proteins to IgG.

Main Results:

• IgG fused to enhanced green fluorescent protein (EGFP) lost fluorescence during refolding.
• IgG fused to Superfolder GFP (SFGFP) and mCherry retained both antigen-binding ability and fluorescence.
• Tandem SFGFP fusions to IgG enhanced fluorescence intensity proportionally.

Conclusions:

• The Inclonals technology can successfully produce functional fluorescent IgG fusion proteins in E. coli.
• SFGFP and mCherry are suitable fluorescent proteins for IgG fusion applications.
• These E. coli-derived fluorescent IgGs present a viable, cost-effective alternative to animal-derived fluorescent antibodies.