Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.08.13.249722v1?rss=1 Authors: Bowen, J. D., Bacon, K. B., Reese, H. R., Rao, B. M., Menegatti, S. Abstract: This work presents the first use of yeast-displayed protein targets for screening mRNA display libraries of cyclic and linear peptides. The WW domains of Yes-Associated Protein 1 (WW-YAP) and mitochondrial import receptor subunit TOM22 were adopted as protein targets. Yeast cells displaying WW-YAP or TOM22 were magnetized with iron oxide nanoparticles to enable the isolation of target-binding mRNA-peptide fusions. Equilibrium adsorption studies were conducted to estimate the binding affinity (KD) of selected WW-YAP-binding peptides: KD values of 37 M and 4 M were obtained for cyclo[M-AFRLC-K] and its linear cognate, and 40 M and 3 M for cyclo[M-LDFVNHRSRG-K] and its linear cognate, respectively. TOM22-binding peptide cyclo[M-PELNRAI-K] was conjugated to magnetic beads and incubated with yeast cells expressing TOM22 and luciferase. A luciferase-based assay showed a 4.5-fold higher binding of TOM22+ yeast compared to control cells. This work demonstrates that integrating mRNA and yeast display accelerates the discovery of biospecific peptides. Copy rights belong to original authors. Visit the link for more info