Generation and verification of dual functional yeast display/secretion system.

Yeast surface display is widely used in antibody discovery and optimization. However, traditional yeast display system could only display the antibody on the cell surface without the secretion of antibody to the cell culture supernatant for direct affinity measurement. To solve this problem, we generated the dual functional yeast display/ secretion system that displayed antibody crystallizable fragments (Fc) with Knob modified as "bait" to capture half molecular immunoglobulin (IgG) with Hole mutation, and secreted fully IgG assembled by Hole-Hole homodimer to the culture supernatant. Results showed that the heavy chain constant region 3 of immunoglobulin with Knob mutation was the best "bait" for antibody display. The dual functional yeast display/secretion system could not only efficiently identify the strains displayed high affinity antibodies from spiking library but also secrete the antibodies to the supernatant for direct affinity measurement. This study proves that the dual functional yeast display/ secretion system was successfully used for antibody affinity maturation, resulting in marked acceleration of the process. : [ABSTRACT FROM AUTHOR]