Protein Expression Systems
Many engineered/designer proteins or single-chain antibodies are poorly expressed. Fusion with SUMO/SUMOstar enhances the stability, solubility, and yield of a protein. SUMO is one of the most conserved proteins in eukaryotes and have been shown to post-translationally modify a number of proteins in cells. SUMOylation plays an important role in various cellular process such as nuclear-cytosolic transport, transcriptional regulation, and protein stability. Few years ago, LifeSensors has developed SUMO- and SUMOstar-fusion technologies to gain prominence for expressing proteins that were difficult to express. SUMO/SUMOstar-fusion leads to a dramatic enhancement of expression in E. coli, yeast, insect, and mammalian cells and promotes correct folding and hence biological activity. Additionally, this system simplifies and lowers the costs associated with protein expression and purification. Using this technology, a plethora of proteins have been shown to enhance their expression, stability, and yield.
Expression in E. coli
Bacterial expression is the usual starting point for expression of heterologous proteins. Bacterial fermentations are inexpensive and can reach high cell densities resulting in high volumetric yields of the target protein. Our SUMO fusion technology is ideally suited for this system.
Expression in Yeast
As with bacterial expression systems, yeast offer relatively inexpensive growth media and high density fermentation. Furthermore, yeast offer the capability of carrying out limited post-translational modifications such as disulfide bond formation and glycosylation. We offer two yeast expression systems, one for intracellular expression in S. cerevisiae and the second for extracellular expression in P. pastoris.
Expression in Insects
Baculovirus/insect cell systems have found wide application for the expression of highly recalcitrant proteins such as protein tyrosine kinases. We have developed a SUMOstar-based system to support expression studies in this system.
Expression in mammalian cells
Mammalian cell expression has become the system of choice for production of complex, glycosylated biotherapeutic proteins such as antibodies, growth factors and fertility hormones. Our SUMOstar system has been designed for transient transfection or stable expression in HEK293 or CHO cells.