Fig. 3. Cell permeability, protease stability, and PPI inhibition of modified peptides were investigated.

a Structure of peptide 7 consisting of peptide 4E (orange) N-terminally linked via PEG₂ (8-amino-3,6-dioxaoctanoyl) to the cell permeable peptide Tat (grey). b Time-dependent proteolytic stability of the peptides in cell culture media buffer containing 10% foetal bovine serum (c(peptide) = 30 µM) (n = 2 technically independent replicates, error bars = SD). c Intracellular concentration of unlabelled peptides investigated by mass spectrometry (90 min incubation at c(peptide) = 25 µM). Peptides 4 and 4E have concentrations below the lower limit of quantification (LLOQ), therefore they were not detected (n = 2 biologically independent replicates, error bars = SEM). d In vitro competition pull-down is performed with a complex of recombinant GST-hTEAD1 and two-helix motif peptides in presence of synthetic biotin-VGL4 immobilized on streptavidin magnetic beads; after incubation for 2.5 h, hTEAD1 pull-down is analysed by SDS-PAGE (n = 1 replicate). Source data are provided as a Source Data file.