Recombinant Conigen Soluble Proteins Mimicking Native Conformations
The CSP technology platform consists of soluble recombinant dimeric and trimeric proteins with a quaternary structure mimicking the natural conformation of protein complexes on cell surfaces, such as receptors or cancer target proteins. These recombinant dimers and trimers enable more biologically relevant translational research and therapeutic antibody discovery.
How it Works
Recombinant ectodomains are genetically engineered with a proprietary cis-dimer motif and stabilization domain at the C-terminus. This promotes spontaneous dimer formation while preserving native structure and orientation. All proteins are expressed in mammalian systems to retain essential post-translational modifications.
Design features:
- Type I transmembrane protein ectodomains
- Parallel dimeric configuration via proprietary linker
- Mammalian expression for native glycosylation and folding
- Fc-free design (motif <50 amino acids) minimizes steric interference
Class of proteins: immune chckpoint proteins, tumor associated antigens, cytokine receptor proteins, T-cell receptor proteins, growth factor receptor proteins, B-cell receptor proteins and siglec proteins
Scientific Rationale
Dimerization is not just structural — it’s essential for function. Many immune receptors, such as CD4 or IFNαR1/2, rely on multimeric configurations for ligand engagement and downstream signaling. Traditional recombinant formats often fail to replicate these quaternary structures, leading to poor assay sensitivity and inconsistent biological readouts.
CSP™ dimers resolve these issues by:
- Accurately modeling native protein-protein interactions, validated by computational modeling
- Delivering 10x greater receptor-ligand binding potency compared to monomer
- Providing more consistent screening performance across platforms (ELISA, SPR, BLI, flow cytometry)
- Supporting epitope accessibility for better antibody generation
Homodimer vs Monomer
CD4 Dimer Binding to Ligand HIV-1 gp120
- 10-fold increase in binding potency compared to monomer
- Conigen CD4 dimer (EC50 0.05 μg/ml)
- CD4 monomer (EC50 0.52 μg/ml)
Heterodimer vs Monomer
Cytokine IFNα Binding to IFNα Receptor Molecules
- Conigen IFNαR1/R2 heterodimer (EC50 4.1 μg/ml)
- R1 monomer (too weak to calculate EC50)
- R2 monomer (too weak to calculate EC50)
CSP Applications
As an Immunogen
Presents more conformational epitopes compared to monomers, to generate antibodies for translational research and therapeutic discovery
As an Antigen
Screen and characterize antibodies targeting diverse epitopes including quaternary conformational epitopes
Drug Screening
Agonist or antagonist screening for research and therapeutic discovery
Characterization
Antibody and drug bioactivity
CSP Advantages
Comparing to cell-based assays for bioactivity
- Cell line isn’t always available for the target of interest
- CSP can preserve the native conformations similar to those on cell surfaces
- Easy to scale-up and high-through-put assays
Comparing to monomeric proteins of the extracellular domains for bioactivity measurements
- CSP not limited to monomeric proteins without critical conformational epitopes on the quaternary structures
- Provides better conformational epitopes for antibody screening and affinity evaluation
- Enhances assay sensitivity and potency; generates wider windows for agonist and antagonist activity evaluation
- Better conformation for antibody/antigen, receptor/ligand complex structural analysis
Comparing to whole cell immunization
- Preserves the native conformations similar to those on cell surfaces
FAQs
How stable are the multimeric soluble proteins?
The stability of the purified recombinant multimeric proteins is comparable to the stability of other recombinant proteins. These proteins are stable for at least 6 months when frozen (-70°C) or at least 7 days at 4°C. Like most recombinant proteins, excessive vortexing, dilution, and freeze-thaw should be avoided to minimize sample and activity loss. More information can be found on the datasheet.
Can multimeric soluble proteins be labeled or modified?
The recombinant multimeric proteins can readily be modified. Please contact Conigen to request tag-free, a special tag, biotinylated or fluorescently labeled molecules.
What quality control standards are used for the multimeric soluble proteins?
The Conigen validation process involves various analytical techniques for each batch, including techniques such as SDS-PAGE, Western blot, and ELISA
How do I order multimeric soluble proteins?
Please contact Conigen using the Consultation request form.
How do I order custom services for multimeric soluble proteins?
Please contact Conigen using the Consultation request form.
What is the lead time for custom services for soluble proteins?
The turnaround time of custom orders is approximately 6-8 weeks from sequence to product. Please contact Conigen using the Consultation request form for more information.
References
- Wright GJ. 2009. Signal initiation in biological systems: the properties and detection of transient extracellular protein interactions. Mol Biosyst 5:1405-12.
- Brown JH. 2006. Breaking symmetry in protein dimers: designs and functions. Protein Sci 15:1-13.
- Atanasova M, Whitty A. 2012. Understanding cytokine and growth factor receptor activation mechanisms. Crit Rev Biochem Mol Biol 47:502-30.
- Mei G, Di Venere A, Rosato N, Finazzi-Agro A. 2005. The importance of being dimeric. FEBS J 272:16-27.
- Marianayagam NJ, Sunde M, Matthews JM. 2004. The power of two: protein dimerization in biology. Trends Biochem Sci 29:618-25.
- Maekawa A, Schmidt B, Fazekas de St Groth B, Sanejouand YH, Hogg PJ. 2006. Evidence for a domain-swapped CD4 dimer as the coreceptor for binding to class II MHC. J Immunol 176:6873-8.
- Matthias LJ, Azimi I, Tabrett CA, Hogg PJ. 2010. Reduced monomeric CD4 is the preferred receptor for HIV. J Biol Chem 285:40793-9.
- Moldovan MC, Sabbagh L, Breton G, Sekaly RP, Krummel MF. 2006. Triggering of T cell activation via CD4 dimers. J Immunol 176:5438-45.
- Li S, Satoh T, Korngold R, Huang Z. 1998. CD4 dimerization and oligomerization: implications for T-cell function and structure-based drug design. Immunol Today 19:455-62.
- Langedijk JP, Puijk WC, van Hoorn WP, Meloen RH. 1993. Location of CD4 dimerization site explains critical role of CDR3-like region in HIV-1 infection and T-cell activation and implies a model for complex of coreceptor-MHC. J Biol Chem 268:16875-8.
- Center DM, Kornfeld H, Ryan TC, Cruikshank WW. 2000. Interleukin 16: implications for CD4 functions and HIV-1 progression. Immunol Today 21:273-80.
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