Extraction and downstream processing of plant-derived recombinant proteins

Area of Science:

• Biotechnology
• Biopharmaceutical Manufacturing
• Plant Molecular Farming

Background:

• Plant-based systems present a low-cost alternative for biopharmaceutical protein production.
• Scalable plant expression systems often involve intracellular protein production in whole plants, necessitating tissue disruption and leading to significant downstream processing (DSP) challenges.
• Existing microbial and mammalian cell platforms have standardized DSP, unlike diverse plant-based systems.

Purpose of the Study:

• To review the challenges and strategies for downstream processing (DSP) of recombinant proteins produced in plants.
• To identify scalable and flexible DSP methods suitable for plant-based expression systems.
• To discuss the potential of plant-derived pharmaceuticals in niche markets.

Main Methods:

• Review of existing DSP platform technologies including centrifugation, filtration, flocculation, and aqueous two-phase separation.
• Discussion of strategies for handling particulate and soluble contaminants from disrupted plant tissues.
• Exploration of generic, flexible, and scalable purification methods like membrane technologies and heat/pH precipitation, adapted for plant-specific contaminants (e.g., RuBisCO).

Main Results:

• Downstream processing (DSP) is a major hurdle for plant-based biopharmaceutical production, particularly for intracellular proteins.
• Clarified plant extracts can be processed using methods similar to microbial or mammalian systems, with adaptations for plant-specific contaminants.
• Protein tags are less desirable than generic, scalable separation strategies for commercial applications.

Conclusions:

• Despite DSP challenges, plant-based systems show promise for niche markets, offering advantages like tailored glycosylation ('biobetters'), rapid scale-up for emergencies, and large-scale commodity protein production.
• Further development of efficient and scalable DSP technologies is crucial for the widespread adoption of plant-based biopharmaceutical manufacturing.
• Plant molecular farming offers unique benefits that can complement, rather than entirely replace, established biopharmaceutical production platforms.