Phor21

Phor21 is a synthetic, 21-amino acid lytic peptide characterized by an amphipathic alpha-helical structure (sequence: KFAKFAKKFAKFAKKFAKFAK). It acts as a cytotoxic agent by physically disrupting and permeabilizing the plasma membranes of target cells, leading to rapid cell death via necrosis or lysis. This mechanism is independent of intracellular signaling pathways or receptor-mediated apoptosis, making it potentially effective against multi-drug resistant (MDR) tumors. Phor21 is primarily utilized as a cytotoxic payload or "warhead" in targeted delivery systems, such as the Pep-1-Phor21 hybrid peptide, which targets the Interleukin-13 Receptor alpha 2 (IL-13Rα2) frequently overexpressed in prostate cancer and other malignancies. By fusing the lytic peptide to a specific ligand, researchers aim to achieve selective destruction of cancer cells while minimizing systemic toxicity.