Figure 1.
Schematic representation of yeast surface display vectors used in this study. Antibody fragment constructs are tethered to the cell wall of S. cerevisiae cells by C-terminal fusion with the Aga2p subunit of the a-agglutinin yeast cell surface anchor protein. Expression is controlled by the tightly regulated galactose-inducible Gal1 promoter. Aga2-ss: native signal sequence of Aga2p for secretion of the constructs. Single-chain antibody fragments (scFv, scFabΔC and sc60Fab) include flexible linkers connecting the light chain and the heavy chain. pNT Fab is a bigenic plasmid including two identical GAL1 promoters for respective expression of light and heavy chains. Cysteine residues responsible for the formation of the inter-chain disulfide bond connecting CK and CH1 are indicated in red. Expression of antibody fragments can be monitored using the HA tag for all constructs. A 6His-Tag sequence can also be used for the monitoring of heavy chain expression when using pNT Fab.