Cell-based Membrane Protein Expression
One of the conventional expression systems for membrane protein (MP) is cell-based expression system, which is the most widely used system for protein production. Expression may be done to a high level, referred to as overexpression, in cell-based expression system. MP platform at Creative Biostructure has developed a set of cell-based expression systems including bacterial cells, mammalian cells, insect cells, yeasts and plant cells expression systems. We are capable of expressing , isolating, purifying and crystallizing MPs to facilitate the study of their biological functions and to provide valuable information for drug discovery.
Mammalian Cell Systems
Mammalian cell expression system generates high-yield eukaryotic proteins. Mammalian cell lines including CHO, HEK-293, BHK-21, COS-7, etc ., are used for MP expression at Creative Biostructure.
Bacterial Cell Systems
E. coli is the most popular bacterial host for protein expression. Other bacterial host, such as Lactococcus lactis, Bacillus subtilis and Rodhobacter sphaeroides are also available at Creative Biostructure.
Insect Cell Systems
Insect cell lines (Sf9, Sf21) are usually derived from Spodoptera Frugiperda . Insect cell system allows for protein post-translational modifications.
Yeast Cell Systems
Yeast cell is an attractive eukaryotic host of single cell with properties of fast growth rates and high cell densities. Two species of yeast used for recombinant protein production are P. pastoris and S. cerevisiae .
Plant Cell Systems
The production of MPs in plant cells is receiving more attention due to its basic advantages of low risk of contamination, easy to grow and capacity for post-translational modification.
Table 1. Comparison of cell-based overexpression systems used for MP production
| Expression system | Advantages | Disadvantages |
| Bacteria |
Most widely used
Low cost |
No glycosylation
limited post-translational modifications |
| Yeast | Perform post-translational modifications |
Low cell density
Hyperglycosylation may occur |
| Insect cells |
Relatively high expression levels
Glycosylation |
Different lipids compare with mammalian cells
Higher cost |
| Mammalian cells | Produce authentic (mammalian) membrane proteins | High cost and complex work |
Progress in the structural and functional characterization of MPs is impaired by their expression and purification, and successful overexpression often requires extensive fine-tuning. Besides cell-based expression systems, Creative Biostructure has also build up cell-free , Virus-like particle (VLP) , liposome , nanodics , detergent-free , animal-free systems for MPs expression. In order to obtain the desired MPs, expression systems and protocols including vector design and transfer, cultivation conditions, expression strategies, MP extraction, choice of detergents and buffer conditions, etc. will be individualized according to the requirements of each particular MP. Please see the list of membrane proteins provided by Creative Biostructure. Feel free to contact us for a detailed quote!
Ordering Process
Reference
Marreddy R., Geertsma E., Poolman B., (2011). Recombinant membrane protein production: past, present and future. Supramolecular Structure and function. Chapter 1.
