Recombinant Antigens: Selecting an Expression System
There are many variables to consider when producing recombinant proteins, and more specifically recombinant antigens. These variables include construct design, affinity tags, expression system, purification scheme, formulation, and characterization. Here we will focus on selecting an appropriate expression system for recombinant antigen production.
Bacterial cells are an economical expression system for production of recombinant antigens for use in in vitro immunoassays. However, endotoxin removal is required if the antigen is intended for antibody production via animal immunization. It is also important to note that a eukaryotic antigen recombinantly produced in bacteria may exhibit altered structure and function when compared to its native counterpart. Although mammalian cells are a more expensive expression platform, they eliminate the need for endotoxin removal prior to immunizations. Moreover, mammalian cells conserve the post-translational modifications of eukaryotic proteins, making them nearly identical to native antigens.
Proteos is an industry leader in the production of high-quality recombinant protein antigens for drug discovery research, utilizing mammalian cell, insect cell, and bacterial expression platforms. We offer transient expression in fully licensed HEK (human embryonic kidney) or CHO (Chinese hamster ovary) cells lines, baculovirus mediated expression in Sf9 (Spodoptera frugiperda) and Tni (Trichoplusia ni) insect cell lines, and prokaryotic expression, in E. coli.
All available expression platforms utilize fully validated protocols for consistent and reproducible results. Typical production times are 6-10 weeks including construct design, expression, and purification. Complete molecular biology services, from construct design to endotoxin free plasmid DNA isolation, are also available.
Contact Proteos today to find the right expression system for your drug discovery research project. We will guide you through the process and design a custom quotation that fits your specific project needs.