Has antimicrobial activity against most Gram-positive and Gram-negative bacteria, filamentous fungi and yeasts tested. Has trypanolytic effect on T.b.rhodesiense and limited hemolytic activity against bovine red blood cells. May play an important role in protecting the stored blood in the anterior midgut from microorganisms prior to digestion. Adopts an amphipathic alpha-helical structure only in the presence of an organic solvent that mimics a phospholipid membrane. Constitutively expressed in the adult anterior midgut; proventriculus, thoracic and reservoir regions.