Fig. 1. All clones are sequence verified and data is provided.

Click on figure to enlarge

From gene synthesis to purified protein
Genosphere Biotech’s Protein Production team provides services at all stages of the protein expression, production and purification processes.

We can use your provided cDNA or else you may want to consider a de novo total gene synthesis. the latter approach is recommended to improve the chances of high heterologous expression: To help solve the issues related to codon bias, the wild-type DNA sequence may be re-defined through codon changes using the appropriate usage frequency table for the host organism: that’s codon optimization. This general approach has been verified to significantly improve heterologous protein expression in numerous cases. You may also wish to add tags for purification, or restriction sites for easy manipulation

Expression systems Our experienced staff routinely supplies proteins expressed in various systems:
 E. coli expression system
 Baculovirus expression system
 Mammalian expression system

Procaryotic E. coli system has several advantages, including ease of culture, rapid cell growth and relatively simple purification procedures. However, one should consider that eukaryotic post-translational modifications are not processed by bacteria, and many proteins are expressed as insoluble inclusion bodies and are very difficult to recover as functional proteins.

Eukaryotic systems for the expression of protein include baculovirus/insect cells and mammalian cells. These systems are more complex to handle and more demanding for processing and optimization however one often enjoy high levels of expression, no inclusion bodies, and eukaryotic post-translational modifications are processed normally in most cases.

Fig. 2. SDS-PAGE showing various key steps of the purification of a C-terminally (His)6 tagged expressed protein.

Click on figure to enlarge

Protein purification
We will purify your protein containing tags:
 glutathione S-transferase (GST tag)
 6 x histidine residues ((His)6 tag)

Expressed purified protein characterization
 SDS PAGE
 WESTERN Blot for (His)6- or GST-tagged protein

Additional optional services include:
 Endotoxin removal
 LC MS analysis
 Scale up fermentation and purification