Phage display

Phage display is a test to screen for protein interactions by integrating multiple genes from a gene bank into phage.

Like the two-hybrid system, phage display is used for the high-throughput screening of protein interactions. The principle of this method is summarized as follows :

1. The function of protein X is unknown. The protein is used to coat the surface of a small plastic dish.
2. Numerous genes, often all the genes in an organism's genome, are expressed in a library as fusions with the coat protein of a bacteriophage, so that they are displayed on the surface of the viral particle.
3. This phage-display library is added to the dish. After a while, the dish is washed.
4. Phage-displaying proteins that interact with protein X remain attached to the dish, while all others are washed away. DNA extracted from interacting phage contains the sequences of interacting proteins.

A phage will target another phagemid and insert its DNA between the signal and the native DNA, the result of this foreign DNA causes the phagemid to secrete a specific amino acid sequence coding for the foreign DNA.

Phage display is also a widely used method for in vitro protein evolution (also called protein engineering). Competing methods for in vitro protein evolution are yeast display, bacterial display, ribosome display, and mRNA display.

See also

• Two-hybrid system
• Protein-protein interactions

See also

• [1] Phage display for selection of novel binding peptides, Sidhu, S. S., Lowman, H. B., Cunningham, B. C., and Wells, J. A. (2000), Methods Enzymol., 328, 333–363

• Selection Versus Design in Chemical Engineering