Abstact

Defensins are small effector molecules of the innate immune system that are present in almost all organisms including plants and animals. These peptides possess antimicrobial activity against a broad range of microbes including bacteria, fungi and viruses and act as endogenous antibiotics. α-Defensins are a subfamily of the defensin family and their expression is limited to specific tissues. Equine DEFA1 is an enteric α-defensin exclusively secreted by Paneth cells and shows an activity against a broad spectrum of microbes, including typical pathogens of the horse such as Rhodococcus equi, various streptococci strains, Salmonella choleraesuis, and Pasteurella multocida. Here, we report the three-dimensional structure of DEFA1 solved by NMR-spectroscopy and demonstrate its specific function of aggregating various phospholipids.