Solid-Phase-Biopanning
Dynabeads® are the ideal solid support for biopanning techniques such as phage display (1) and SELEX®. They have been used to identify targets for therapy (2), diagnostic markers (3) and to generate lead molecules in drug discovery (4).

Biotinylate the target ligand, couple it to Dynabeads® Streptavidin and then expose to the phage or random DNA library. You can then separate the positive binders from negatives by magnetic handling.  Alternatively, you can immobilize your ligand using Secondary-Coated Dynabeads®,  Dynabeads® Protein A,  or Dynabeads® Protein G, or a selection of Surface-Activated Dynabeads®.

Biopanning with Dynabeads® offers many advantages over plates, including:

  • Correct orientation of the binding domain by directed biotinylation of the ligand.
  • Minimal conformational changes of the immobilised target.
  • Increased surface area allows for panning of saturated phage solutions.
  • A higher percentage of positive binders and fewer rounds of panning.
  • Magnetic separation allows for automation high throughput panning.

Phage display library screening is a valuable tool for protein-protein interaction mapping.

Dynabeads® Streptavidin have also been used to generate antigen-specific monoclonal antibodies in vitro. Ligands are immobilized on the beads, and high-affinity binders selected and matured by using a hypermutating B-cell line with only four rounds of sorting (5).
Dynabeads® are widely used in automated devices for panning for drug candidates, and a number of companies worldwide are benefiting from the unique properties of the Dynabeads® Streptavidin.

References

  1. Nord K. et al. (2001). Recombinant human factor VIII-specific affinity ligands selected from phage-displayed combinatorial libraries of protein A. Eur. J. Biochem. 268:4269-4277.
  2. Biroccio A. et al. (2002). Selection of RNA aptamers that are specific and high-affinity ligands of the hepatitis C virus RNA-dependent RNA polymerase. J. Virol. 76(8):3688-3696.
  3.  Legendre D. et al. (1999). Engineering a regulatable enzyme for homogenous immunoassays. Nature Biotech. 17:67-72.
  4.  Lev A. et al. (2002). Isolation and characterization of human recombinant antibodies endowed with the antigen-specific, major histocompatibility complex-restricted specificity of T-cells directed toward the widely expressed tumor T-cell epitopes of the telomerase catalytic subunit. Cancer Res. 62(11):3184-3194
  5.  Cumbers SJ. et al. (2002). Generation and iterative affinity maturation of antibodies in vitro using hypermutationg B-cell lines. Nat. Biotech. 20(11):1129-1134.
  6. Demartis S. et al. (1999). A strategy for the isolation of catalytic activities from repertoires of enzymes displayed on phage. J. Mol. Biol. 286:617-633.
  7.  Pini A. et al. (1998). Design and use of a phage display library. J. Biol. Chem. 273(34):21769-21776.
  8.  Cox JC. et al. (2002). Automated selection of aptamers against protein targets translated in vitro: from gene to aptamer. Nucleic Acids Res. 30(20):e108.