Dramatic Enhancement of Therapeutic Proteins with SUMO

Mammalian cells no doubt became the factories of recombinant protein production, especially for antibodies. However, production of therapeutic proteins, such as cytokines, chemokines, and growth factors remains a problem, especially when the desired N-terminus is required for biological activity. SUMO-fusion system has emerged as an ideal way to increase production of proteins: SUMOpro for E. coli and SUMOstar for mammalian cells (see below for distinction).

Read More: Understanding SUMO

It is important to understand why the SUMO system has proven to be the best among all other fusion systems (consult LifeSensors’ SUMO Search Sheet). The chaperoning properties of SUMO promote correct folding and protect the fusion partner from degradation. These factors contribute to dramatically enhance protein production and improve the quality of the fusion partner. Many therapeutic proteins require defined N-termini for biological function. The SUMO system is the most cost-effective way to generate the desired N-terminus of the protein. Nature designed SUMO to chaperone proteins in the cell. LifeSensors captured the SUMO and SUMOstar chaperoning properties for protein production. LifeSensors can guide scientists about the most suitable SUMO tag and SUMO protease to efficiently remove SUMO to reduce the cost of goods. LifeSensors can guide your cloning strategy to selection of strains/cell lines for the best expression and establish a non-GMP process from gene to protein. The process can be easily adapted for downstream GMP production of proteins.

The SUMO Tag

SUMO (Small Ubiquitin-like Modifier) is a member of the ubiquitin family, composed of a flexible N-terminal region followed by a ball-shaped ubiquitin-like fold. SUMO’s hydrophobic core improves correct folding of the fused proteins, and hydrophilic surface keeps the partner protein soluble. SUMO protease recognizes SUMO structure to cleave at the junction to generate desired/physiological N-terminus of the partner proteins.

Workflow schematic of TUBE proteomics

Figure 2: The Principle of the system. SUMO Protease cleaves the SUMO 6xHis tag to separate the expressed protein of interest. The 6xHis is used to assist in purification while SUMO or SUMOstar enhanced protein productions.

the protein structure of SUMO

Figure 1: The unique string and ball structure of SUMO allows for improved expression due to a hydrophilic outer surface and a hydrophobic core.

Distinction Between SUMOpro and SUMOstar: Expression of Therapeutic Proteins in Mammalian Cells

The SUMO pathway is conserved in eukaryotic cells. E.coli lacks the SUMO pathway and SUMO proteases. Unlike SUMOpro that is used to express SUMO-fusion in E.coli, native SUMO-fusions are rapidly cleaved in eukaryotic cells. To circumvent this problem and to take advantage of cheapening the properties of SUMO, the SUMO tag is engineered to preserve enhanced protein production properties of SUMO. The engineered SUMO is called SUMOstar. SUMOstar fusions are not cleaved by endogenous eukaryotic SUMO proteases. The isolated SUMOstar fusions from eukaryotic cells can be efficiently cleaved by SUMOstar protease in vitro.

LifeSensors offers both SUMOpro and SUMOstar for expression of chemokines, cytokines, and growth factors. Over 1000 proteins have been expressed as SUMOpro or SUMOstar fusions. Check to see if your protein or member of the family has been expressed as SUMO-fusion by using the included SUMO Search Sheet (below).

The SUMO system allows for the expression of mature protein with the desired N-terminus. SUMO protease is used for removing SUMO fusion manufactured in E. coli, and SUMOstar for processing fusion proteins from mammalian cells by SUMOstar protease. Application of SUMOstar in mammalian cells preserves post translational modifications, enhanced biological activity, and yield. LifeSensors can evaluate your gene for expression enhancing properties by SUMOpro and SUMOstar in mammalian cells (results delivered in 2-4 weeks). These methods can be transferred to downstream processing labs for GMP production.

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Click for: Lifesensors' SUMO Publication Searchable Sheet

To use, simply utilize the drop down arrows in order to search for your target of interest or application category. Lifesensors SUMO technology has been utilized for the expression of many different targets and continues to be utilized worldwide.

Lifesensors has pioneered SUMO technologies and discovery, and is looking forward to sharing these discoveries and applications with the greater pharmaceutical and biotech community.

Preview our Therapeutic Protein Expression Presentation
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