Peptide Database

Human Neutrophil Peptides (HNP-1, HNP-2, HNP-3) · α-defensins

Alpha-defensins are cationic antimicrobial peptides secreted by neutrophils (HNP-1 to 4) and Paneth cells (HD-5, HD-6) in the small intestine. They kill bacteria, fungi, and enveloped viruses through membrane disruption and also function as chemokines, recruiting immune cells and bridging innate and adaptive immunity. Paneth cell alpha-defensins (HD-5, HD-6) play a critical role in shaping intestinal microbiome composition.

Magainin II

Magainin-2 is a 23-amino-acid cationic antimicrobial peptide (AMP) isolated from the skin of the African clawed frog (Xenopus laevis). It kills bacteria through membrane disruption — forming toroidal pores in bacterial lipid bilayers — while showing low toxicity to mammalian cells due to differences in membrane composition. It is a key model peptide for AMP research and drug design, with a derivative (pexiganan) evaluated in clinical trials for diabetic foot ulcers.