Yeast display

The yeast display is a biochemical method with the recombinant proteins and peptides based on their binding properties ( affinity), or may be identified and evolved according to their catalytic activity. To members of a protein library of the cell surface of yeast is presented. The yeast display is an in vivo molecular variant of the display.

Principle

Substantially all molecular display systems is the coupling of genotype and phenotype, i.e., which is covalently or non- covalently linked by compartmentalization associated with the genetic information to be screened protein. The principle of molecular displays based on the common occurrence of a protein and its encoding DNA and in a particle or a cell ( in this case, there are yeasts ), whereby on the basis of binding to an already existing molecule interaction partner transgenic from a mixture of yeasts can be isolated and propagated whose DNA is then present as well. The recombinant surface protein corresponding DNA sequence is then extracted, copied by PCR and sequenced by DNA sequencing. Via the genetic code, then the amino acid sequence of a binding protein is known.

To identify a binding partner gene libraries can be cloned into the gene AGAP2. Directed evolution, a fusion protein of the protein to be modified is produced by the surface protein of Aga2p. Aga2p stands out from the glycocalyx of the cell membrane of yeasts and is naturally the cell -cell contact in mating yeast. In the fusion protein of the protein-binding part of the Aga2p was replaced by the protocol to change or to be identified protein. By MACS or FACS, the binding to its target protein ( affine ) cells are selectively isolated.

Advantages of the yeast displays compared with the in vitro and the prokaryotic process is the eukaryotic glycosylation of the displayed protein and the protein quality control. The disadvantages are similar to humans, but not identical glycosylation in yeast and the comparatively smaller gene library.

Applications

The yeast display is used for the selection and directed evolution, inter alia, recombinant antibodies.