Penetratin peptide

Penetratin is a cell-penetrating peptide (CPP), also known as a protein transduction domain (PTD), of which the first 16 amino acids are derived from the third helix of the Antennapedia protein homeodomain. Penetratin linked to a phosphodiester oligonucleotide is capable of permeating through neuronal cell membranes and down-regulating genes.