Fig. 3. Phage selection of HDM2-binding peptide ligands. (a) Screening scheme of the stapled peptide tethered phage library (HDM2-R1, R2 or R3: selected phage pools after single, double or triple binding selections, respectively). (b) Diversity plots of phage pools after selection. All unique sequences obtained by NGS analysis were grouped by their abundance (coloured segments). For instance, the grey segment (<105) contains unique sequences counted only a single time. For each coloured segment, the number of unique sequences and the proportion of total reads are shown on the x- and y-axes, respectively. (c) The top 20 sequences in HDM2-R3 pools. Peptides (c13 and c17) containing F, W and L/I at i, i + 4 and i + 7 positions are coloured red. (d) Phage ELISA results against immobilised HDM2. Error bar represents SD (n = 3). (e) Relative infectivity of phages. The titres of each phage were normalised by that of model phage containing the S̲CG̲G̲S̲G̲G̲S̲CS̲ sequence. Error bar represents SD (n = 3).
