Antibacterial derived from the N-terminus of papiliocin.

Pap12-6 is an antibacterial peptide derived from the 12 amino acids in the N-terminus of papiliocin, a cecropin found in swallowtail butterfly larvae. Pap12-6 possesses broad-spectrum antibacterial activity, especially against multidrug-resistant Gram-negative bacteria, acting by permeabilizing the bacterial membrane. Pap12-6 significantly reduces the secretion of NO, TNF-?, and IL-6 and also shows anti-inflammatory activity via a TLR4-mediated NF-κB signaling pathway. In a mouse sepsis model, Pap12-6 significantly improved survival, reduced bacterial growth in organs, and reduced LPS and inflammatory cytokine levels.