Quantitative evaluation of the relative cell permeability of peptoids and peptides

Abstract

We evaluated quantitatively the relative cell permeability of peptoids and peptides using a cell-based reporter gene-based assay. Generally, peptoids were much more cell permeable than the corresponding peptides, though the difference decreased with increasing length. These results suggest that peptoids may be useful reagents for manipulating the activities of intracellular proteins.

Figure 1

Chemical structures of the compounds employed in this study.

Figure 2

Fluorescence polarization assay for in vitro GR binding affinity. The displacement of a fluorescein-labeled dexamethasone was monitored by fluorescence polarization. The data were plotted as the milipolarization units (mP) versus the concentration of the competitors. IC₅₀ values are shown in Table 1.

Figure 3

Dose dependent induction of luciferase expression. Luminescent intensities were measured 40 h after treatment of each compound at various concentrations with a dual-luciferase reporter assay system. The data were plotted as the fold induction of luciferase activities versus the concentration of the compounds. EC₅₀ values are summarized in Table 1.