Production of recombinant proteins routinely encounters problems, including the formation of inclusion bodies, incorrect protein conformation, toxicity to the host cell, or low protein yield. These issues are most often addressed by changing expression hosts or through fusion of the protein of interest (POI) to a carrier protein (fusion tag). Located at either the N or C- terminus of the protein of interest, fusion tags can improve protein solubility, achieve native protein folding, and increase total yield by improving expression and decreasing degradation. LifeSensors has pioneered SUMO (Small Ubiquitin Like Modifier) Fusion technology that has remarkable effect on increasing quantity and quality of recombinant proteins in prokaryotes and eukaryotes.
LifeSensors SUMO-Fusion Platforms: LifeSensors has developed a number of patented SUMO-fusion vectors that are suitable for expression in E. coli, yeast, insect and mammalian cells. SUMO is present in eukaryotes and absent from prokaryotes. Thus, LifeSensors' SUMOpro platform is designed specifically for E. coli. In E. coli, SUMO-fusions are expressed as intact proteins. Rapid isolation of the E. coli-expressed fusion is achieved by an N-terminal His tag on the SUMO-fusion, which enables nickel affinity purification. To ensure that the wide variety of possible SUMO-fusions are cleaved, LifeSensors has developed both a recombinant SUMO protease, and a versatile, engineered SUMO protease II that will cleave fusions not cleavable by SUMO protease. Since E. coli does not have an endogenous SUMO pathway, intact SUMOpro fusion proteins are expressed and SUMO tag is removed by SUMO protease. In contrast, since the native SUMO pathway is present in eukaryotes, SUMOpro fusions are rapidly cleaved in insect, yeast and mammalian cells. Therefore, LifeSensors has developed a eukaryote-compatible orthogonal system. SUMOstar is a purpose-engineered system that preserves the chaperoning properties of SUMO in eukaryotes. SUMOstar fusions are resistant to cleavage by endogenous SUMO proteases in eukaryotic hosts, and can thus be expressed in eukaryotes and subsequently cleaved by the engineered SUMOstar protease. LifeSensors holds a number of U.S. and worldwide patents on applications of SUMO technologies to manufacture proteins in E. coli, yeast, insect or mammalian cells.Read More >
Protein on Demand/Superior Expression System: Take advantage of LifeSensors' expertise in protein expression and our ability to apply SUMO-fusion technology to your difficult-to-express proteins. LifeSensors' SUMOpro and SUMOstar systems will dramatically improve the quality and quantity of your most challenging recombinant proteins. Attachment of SUMO to the N-terminus of difficult-to-express proteins stabilizes those proteins in cells and increases protein yield. Misfolded proteins precipitate in inclusion bodies and thus become inactive. The hydrophilic nature of SUMO allows it to enhance the solubility of fusion proteins, facilitating correct protein folding. Many fusion tags don't afford generation of the desired N-terminus following tag cleavage with a protease. SUMOpro and SUMOstar proteases have the remarkable ability to cleave at the C-terminus of SUMO irrespective of any residue at its junction with the fusion protein (except proline), generating the native N-terminus. There is strong evidence that a protein's N-terminal residues dictate its half-life in vivo: the so-called N-end rule. SUMO systems allow you to take advantage of the N-end rule to increase the half-life of your proteins. These advantages are not offered by any other fusion system. We invite you to consult with our senior scientists to learn more about the application of SUMO technologies to your difficult-to-express proteins.
How to leverage the SUMO system: The SUMO system has been utilized by researchers around the globe to overcome inefficient protein expression. In this section, we have compiled a brief list of real-world applications of our SUMO Fusion technology.