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pCon Plus Constant Region Vectors 

The pCon Plus vectors are an easy way to re-express whole antibodies. The GS Xceed® expression vectors were modified to contain the constant region of a range of immunoglobulins (Ig) (see table below for full details). Along with the genetic elements of the Ig variable regions, these pCon Plus vectors offer easy construction of a library of full length antibodies with human constant regions.  

Benefits include:  

  • Easy sub-cloning of variable regions with a single ligation step
  • Fast construction of chimaeras or fully humanized mAbsWide range of available isotypes and allotypes  
  • Gene optimized DNA sequences 

 

Available Isotypes and Allotypes

Constant Region
Heavy Chain  Light Chain
Isotype  Allotype  Isotype Allotype
 IgG1  f, za and zax  Lambda2 N/A 
 IgG2  n-  Kappa  Km(3)
 IgG3  g    
 IgG4  N/A*    

*more stable hinge mutant available

NB: IgG1, IgG2 and IgG4 constant region genes are also available where the codon for the C-terminal lysine has been removed

 

Site Specific Conjugation Constant Region Vectors

The Site Specific Conjugation (SSC) vectors are an easy way to produce conjugation-competent antibodies. pCon Plus Constant Region Vectors, part of the GS Xceed System®, were modified to contain point mutations to introduce cysteine residues at defined positions in the constant region of an immunoglobulin heavy or light chain (Figure 1).   Mutations are introduced as a single point mutation at a single site in either the heavy or light chain.  The table below identifies options including six variants in the heavy chain and two variants in the light chain.  

Combining these vectors with the genetic elements of the Ig variable regions offers easy construction of a library of full-length antibodies with human constant regions including a defined number and location of bioconjugate attachment points. The conjugation sites have been assessed for aggregation and immunogenicity impact. In conjunction with our pCon Plus vectors, antibody libraries with fine-tuned conjugation capabilities and drug-to-antibody ratios (DAR) of 0,[GdlcR-C1] [BG-C2]  2 and 4 can be constructed using standard thiol chemistry under mild conditions.  Applications include antibody drug conjugates (ADCs), half-life extension and imaging.  

Benefits include:

  • Easy sub-cloning of variable regions with a single ligation step
  • Fast construction of conjugation enabled chimeric or fully humanized mAbs
  • Gene optimized DNA sequences  

 

 

 Figure 1. Available conjugation sites are highlighted in red (heavy chain) and green (light chain)

  

Available Heavy and Light Chain Variants

 Site Specific Conjugation Vectors
 Heavy Chain  Light Chain
 Isotype/Allotype Number of Variants Isotype/Allotype Number of Variants
 IgG1f 6 Kappa(Km3)) 2