Helix-Stabilized Cell-Penetrating Peptides for Delivery of Antisense Morpholino Oligomers: Relationships among Helicity, Cellular Uptake, and Antisense Activity

The secondary structures of cell-penetrating peptides (CPPs) influence their properties including their cell membrane permeability, tolerability to proteases, and intracellular distribution. Herein, we developed helix-stabilized arginine-rich peptides containing alpha,alpha-disubstituted alpha-amino acids and their conjugates with antisense phosphorodiamidate morpholino oligomers (PMOs), to investigate the relationships among the helicity of the peptides, cellular uptake, and antisense activity of the peptide-conjugated PMOs. We demonstrated that helical CPPs can efficiently deliver the conjugated PMO into cells compared with nonhelical CPPs and that their antisense activities are synergistically enhanced in the presence of an endosomolytic reagent or an endosomal escape domain peptide.

Automated summary

This study developed helix-stabilized arginine-rich peptides and their conjugates with antisense phosphorodiamidate morpholino oligomers (PMOs) to investigate the relationships among peptide helicity, cellular uptake, and antisense activity.