Plasmid for the expression and production of non-native proteins in Geobacillus stearothermophilus at high temperatures.
- Allows for improved manufacturing of peptides & proteins at higher temperatures than generally possible.
- High incubation temperature prevents contamination with other bacterial species.
Manufactured proteins are used in many products, such as vaccines, adjuvants, therapeutics, and antibodies. These proteins are synthesized by overexpression of the protein of interest in an organism, with bacterial overexpression being the preferred method. Escherichia coli is the most commonly used organism for this purpose; however, the lower incubation temperature required by E. coli can often lead to contamination with other strains of bacteria, and subsequent difficulties in purification of the protein. There is an unmet need for a method of protein production in a bacterial system that also limits potential contamination by other species.
Researchers at Emory have developed an expression vector for proteins within the thermophilic bacterium Geobacillus stearothermophilus which functions at elevated temperatures. This thermophile enables the expression of thermostable proteins, which are more resilient and valuable than regular mesophilic proteins. This vector consists of a plasmid known to replicate efficiently in Geobacillus stearothermophilus into which any gene for a desired protein can be cloned. This allows expression of the protein from 30 to 75 degrees Celsius, the elevated temperatures at which Geobacillus stearothermophilus survives but most other bacteria cannot. These elevated temperatures would significantly decrease the potential contaminating bacteria and enable engineered strains to produce valuable small molecules more productively than engineered E. coli.
Non-native protein alpha galactosidase has been expressed in Geobacillus stearothermophilus, as a proof of concept model.