Antibody Engineering: Unusual Formats
Antibodies from hybridomas are not the only option when it comes to affinity reagents - there are many methods of generating binders. Some offer interesting structural options (e.g. single domain binders) or a functional advantage (e.g. binding to difficult non-peptide targets).
However, limitations prevent non-antibody binders from becoming widely adopted research reagents:
- There are few commercially available secondary reagents to detect binding and/or amplify signal
- Non-antibody binders have fewer conjugation sites
- Non-antibody binders often have a short in vivo half-life, and can have no effector function
Now, with recombinant technology, Absolute Antibody is overcoming these limitations to make these reagents accessible to researchers across the life sciences.
Case Study: From scFv to IgG
The scFv BG4 recognises G-Quadruplex (G4) nucleic acid structures, which are of interest in the study of genome function. As an scFv, BG4 requires a specialist secondary reagent and a tertiary reagent for visualisation. Absolute Antibody has engineered the BG4 binding domains onto common antibody backbones, making it compatible with the detection reagents already present in most labs.
|Figure: ELISA data showing the activity of engineered BG4 against G-quadruplex (G4) DNA, G4 RNA, and non-G4 DNA.
LEFT: BG4 as a Mouse IgG1; example of binding activity in a dimeric format.
RIGHT: BG4 as Human Fab fragment; example binding activity in a monomeric format.
Our engineered BG4 retains activity against both DNA and RNA G-quadruplex structures. Many thanks to the Balasubramanian Group at the University of Cambridge (who first generated the scFv) for the above data.
Case Study: From scFv to Long-neck-scFv-Fc-Fusion Protein
Trimethylated lysine residues on histone H3 are important epigenetic markers. Absolute Antibody offers two highly selective antibodies specific to two residues of interest - H3K4me3 and H3K9me3.
|Figure: Flow cytometry of mouse spleen cells stained using three different
PD-L1 binders which have been reformatted into rabbit IgG
Grey = anti-PDL1 staining; Purple = isotype control
LEFT originally scFv from chicken derived phage display library
MIDDLE originally camelid VHH
RIGHT originally antibody raised in rat
|Catalog No.||Product Description||Original Format||Example Format(s)|
|Ab00174||Anti-DNA/RNA G-quadruplex [BG4]||phage display scFv||mouse IgG1 and human Fab|
|Ab00373||Anti-PDL1 [YDC 127.1.1]||raised as rat IgG2a||rabbit IgG|
|Ab00377||Anti-PDL1 [alphaPD-L1]||phage display scFv||rabbit IgG|
|Ab00699||Anti-H3K4me3 [304M3-B]||phage display scFv||long neck scFv-Fc|
|Ab00700||Anti-H3K9me3 [309M3-B]||phage display scFv||long neck scFv-Fc|
|Ab00840||Anti-PDL1 [VHH-PD-L1]||raised as camelid VHH||rabbit IgG|