Yeast display has been regarded as an alternative method for isolating and engineering antibody fragments (Fab, scFv) from immune and non-immune libraries. In a general “a-agglutinin” display system, the protein of interest and an HA tag be fused to the C-terminus of the a-agglutinin Aga2p subunit. Following translation, the 69-amino acid Aga2p subunit associates with 725-amino acid a-agglutinin Aga1p subunit via two disulfide bonds. The fusion protein is subsequently secreted to the extracellular space where Aga1p is anchored to the cell wall via a β1,6-glucan covalent linkage. As a result, the protein of interest is displayed on the cell surface where it is accessible by soluble ligands (as shown below).

Features of Yeast Display platform

1. Provides a direct connection between genotype and phenotype.  

2. Eukaryotic translation machinery offers expression similar as mammalian cells.

3. Multivalent display with each cell displaying 104 to 105 copies of the VHH.

4. Accurate control over selection parameters during FACS screening.

5. Real-time kinetic observations during the selection process.

6. Selected binders can be further analyzed by next-generation sequencing (NGS).