Antennapedia peptide Arg – Cell Penetrating Peptides – CPP

Identification of cell penetrating conjugates has aided numerous areas of scientific development. The Drosophila transcription factor Antennapedia contains a homeodomain that can be internalised by cells in a receptor-independent mechanism to the cytoplasm and to the nucleus. The key residues for internalisation have been sequenced (RQIKIWFQNRRMKWKK) and used in several studies to aid entry of recombinant proteins into cells. To further the scope of cell penetrating peptides (CPPs), analogues of penetratin have been generated. This arginine rich acid sequence was made and found to be a strong antimicrobial/antifungal agent while also retaining its CPP properties. The activity was tested against the pathogenic strains Candida albicans, Cryptococcus neoformans, Staphylococcus aureus, and Escherichia coli. The degree of arginine content is linked to the rate of cellular uptake and antimicrobial activity.