Mammalian Protein Expression Services

 

KMD Bioscience has been working on recombinant protein expression and antibody development for many years. For the full-length antibody and glycoprotein biological drug, the folding of expression product polypeptide chain, the disulfide bond, the presence or absence of glycosylation and the type of glycosylation often affect the properties of the synthesis, secretion, biological activity, in vivo stability, and immunogenicity of the expressed product. Mammalian protein expression system is ideal for eukaryotic protein expression because it has the most complicated posttranslational modifications closest to the native ones. Compared with other eukaryotic expression systems, the expression of the target gene in mammalian cells is similar to that of the native protein in the type and manner of the glycosylation, and can be correctly assembled into the multi-subunit protein.

With our well-established a protein expression platform, KMD Bioscience can offer efficient mammalian protein expression services. Our scientists have rich experience in protein preparation by using mammalian cell expression system. Our mammalian transient expression system, mainly use CHO cells and HEK293 cells as expression hosts, can provide flexible services which could meet different custom needs, including tag removal, endotoxin removal, SEC-HPLC assay, glycosylation analysis etc. Meanwhile, we have a variety of fermentation tanks, bioreactors and protein purification systems, which can provide recombinant proteins from milligram level to gram level.

 

Service Process:

 

 

Service Content:

 

Steps

Specification

Timeline

Deliverables

Gene cloning and vector construction

* codon optimization & gene synthesis

* sequencing

1-2 weeks

* Sequencing data    

* Experimental scheme

Transient expression

* Transfect cells (CHO, HEK293) with expression constructs
* Detect expression levels by SDS-PAGE and WB

1-2 weeks

* Expression results
* Experiment report

Stable cell lines (Optional)

* Construction and screening of CHO stable expression cell lines

4-6 weeks


* Recombinant protein

Small-scale protein expression

* Culture expansion of cells

1-2 weeks

* Optimized report

* Culture conditions

* 1-5 mg recombinant protein

Large-scale protein expression and purification

* The recombinant proteins were purified by affinity chromatography, ion exchange chromatography and gel filtration (1L)≥90% purity
* SDS-PAGE

1-2 weeks

* 1-5mg recombinant protein
* Protein purification report
* Tag removal and separation of tag-free protein (if requested)

  

Service Highlights:

 

--Extensive experience in protein expression

--Codon optimization: including rare codon analysis, protein hydrophilicity analysis and prediction of transmembrane domains

--High efficiency and short cycle

--Strict quality control to ensure high-level expression of both intracellular and secreted recombinant proteins

--A variety of fusion tag vectors and hosts to ensure high soluble protein expression and activity

--High-throughput and large-scale protein expression and production

--Various scale-up capacities ranging from 10 to 500 L

--Low endotoxin level: LAL <0.1EU/mg

--One-stop services, including protein purification, protein sequencing, protein labeling and related services