Hyperstable Serum Albumin Variants for Microbial Mass Production

Background and Unmet Need

Albumins derived from animal or human plasma present ethical and reproducibility challenges (e.g., contamination
risks, batch-to-batch variability, and animal welfare). Additionally, the growing demand for serum albumin in the
cultivated meat industry far exceeds the current production capacity of recombinant proteins. While yeast-based
production has been explored, it remains complex. In contrast, bacterial production offers advantages in terms of
speed, cost, and efficiency, but the complex structure of albumin has precluded its heterologous production, until
now.

The Solution

Computationally designed hyperstable variants of mammalian serum albumins readily expressed and purified from E. coli.

Technology Essence
Using the PROSS computational platform, stable designs of human and bovine serum albumins (HSA and BSA)
were developed, exhibiting superior thermal stability compared to plasma-derived counterparts, of up to 40°C and
even beyond the boiling point. The optimized designs were robustly expressed in E. coli in 100s of mg/l culture in
standard lab settings. By contrast, the natural albumins did not express solubly. The engineered HSA and BSA
variants were not toxic to HEK293T and hybridoma cells, carried typical small-molecule ligands of albumins and
exhibited potent activity in restriction enzyme reactions, thus enabling applications in cell culture, and molecular
biology (Figure 1).
Figure 1. Stabilized HSA and BSA designs with improved thermal properties, generated through computational
modeling for cell culture, and biotech applications.

Applications and Advantages

• Fast and economical large-scale production of animal-free reagents
• Applicable to cultivated meat, cell culture and molecular biology applications
• Significantly higher thermal stability, enabling direct purification from bacteria by boiling

Development Status

All tested stabilized variants were highly expressed in E. coli and their functional properties were validated in cell
culture and in vitro applications.