Characterization of a novel helper phage for high valence pIX display

Abstract

Phage display has been instrumental in discovery of novel binding peptides and folded domains for the past two decades, arguably with most success in the field of drug discovery. Despite being a mature and dominating technology, further development continues to broaden the area of application and improve performance beyond the current state of the art. We have recently reported a novel pIX phagemid display system that is characterized by a very strong genotype to phenotype coupling combined with low display levels, two key features that support the highly efficient affinity selection observed. However, high diversity in selected repertoires is intimately coupled to high display levels during initial selection rounds. To incorporate this additional feature into the pIX display system, we have developed a novel helper phage that allows for high valence display on pIX. Until now, the general consensus has been that display on pIX is dependent on wt complementation, making high valence display unattainable. Contrary to this, we present here our novel helper phage that indeed does facilitate high valence pIX-display, with a side-by-side comparison to the current standard in pIII-display. This novel helper phage exhibits characteristics that should make the novel pIX phagemid display platform the system of choice for high affinity selection.