Creative Biolabs now offers specialized membrane protein expression service based on our advanced mammalian cell-based system. With years of devotion, we have gained extensive experience in using cell-based protein expression systems and achieved remarkable success with various challenging membrane protein targets, including GPCRs, ion channels, and transporters.
Expression of recombinant proteins with high yield and appropriate bio-activity is a prerequisite for studies of membrane protein structure and function. However, membrane proteins, acting as transduction receptors, cell adhesion molecules, and transport channels, are known for their difficulty to express and isolate due to the large molecular weight, complicated structure, and various modifications. A variety of cell-based expression systems have been developed including:
Heterologous expression in prokaryotic systems like E. coli may result in the formation of inclusion bodies. Yeast and insect system, although eukaryotic, are deficient of many necessary post-translational modifications and folding process. Moreover, differences in lipid compositions can also impair correct conformation and ligand binding liabilities. Taken together, mammalian cell-based system manifests as the most secure and irreplaceable expression platform for many eukaryotic protein targets.
Figure 1. Illustration of a typical process to perform recombinant membrane protein production in a mammalian cell line. (Pharmaceuticals, 2013)
Creative Biolabs has proprietary Magic™ mammalian protein production from numerous mammalian cell types including human embryonic kidney cells (HEK-293), baby hamster kidney cells (BHK-21), monkey kidney fibroblast cells (COS-7) and Chinese hamster ovary cells (CHO). CHO cells are the abundantly used cell lines in membrane protein production due to their growth ability in suspension systems and bioreactors. HEK-293 cell is also a popular choice. We provide the following different approaches according to the specific needs for membrane protein expression:
Transient transfection system allows for membrane protein production within a few days after the expression plasmid has been constructed, while stable transfection system takes several months for full development. Transient transfection system can employ either cationic compound to facilitate the uptake of plasmid DNA into the cell, or recombinant non-replicative viruses that have evolved to efficiently enter mammalian cells. HEK293 cells are transiently transfected using liposomes, calcium phosphate or PEG as transfection reagents. CHO cells are commonly used to stably express large quantities of recombinant membrane proteins. This process involves transfection of dihydrofolate reductase (DHFR)-deficient CHO cells with the gene of interest and a DHFR selection cassette. The transfected cells are then screened in the presence of methotrexate to obtain stably transfected cell pools.
Eukaryotic membrane protein produced from Magic™ protein expression in mammalian cells system can satisfy the following applications:
Creative Biolabs is a multi-dimensional service and product provider always striving to fulfill clients’ expectations and demands. By using our first-class mammalian expression system, we support not only small-scale expression but also rapid and reliable scale-up production of high-quantity membrane protein products. Alternatively, we also offer custom service based on Cell-free Membrane Protein Expression System. Please feel free to inquiry for more information.