Efficient Delivery of
Cyclic Peptides into Mammalian
Cells with Short Sequence Motifs
- Publication date
- Publisher
Abstract
Cyclic peptides hold great potential as therapeutic agents
and
research tools, but their broad application has been limited by poor
membrane permeability. Here, we report a potentially general approach
for intracellular delivery of cyclic peptides. Short peptide motifs
rich in arginine and hydrophobic residues (e.g., FΦRRRR, where
Φ is l-2-naphthylalanine), when embedded into small-
to medium-sized cyclic peptides (7–13 amino acids), bound to
the plasma membrane of mammalian cultured cells and were subsequently
internalized by the cells. Confocal microscopy and a newly developed
peptide internalization assay demonstrated that cyclic peptides containing
these transporter motifs were translocated into the cytoplasm and
nucleus at efficiencies 2–5-fold higher than that of nonaarginine
(R<sub>9</sub>). Furthermore, incorporation of the FΦRRRR motif
into a cyclic peptide containing a phosphocoumaryl aminopropionic
acid (pCAP) residue generated a cell permeable, fluorogenic probe
for detecting intracellular protein tyrosine phosphatase activities