Penetratin is a 16-mer peptide derived from the third helix of the Drosophila Antennapedia DNA binding domain that is mapped to be responsible for cellular internalization. Penetratin is able to translocate through the plasma membrane to the cytosol and nucleus, and can facilitate internalization of macromolecular cargoes into living cells, usually by the formation of a conjugate or fusion protein. Penetratin is commonly used as an alternative or complement to Tat peptide for enhancing the cellular uptake of nanoparticles.
