They are synthesized by the human protozoan parasite, Entamoeba histolytica , the causative agent of amoebiasis. The major pathogenic effect of E. histolytica is its cytolytic capability which is due to amoebapore which kills target cells. Three isoforms of amoebapore have been isolated and characterized biochemically. The mature proteins are 77-88 amino acids in length, although the precursor proteins are larger.
Active peptides are present inside cytoplasmic granules of the amoeba trophozoite.
Release allows amoebapore to be inserted into the membrane of a target cell without dependency on a specific receptor. The inserted amoebapore protein oligomerizes to form ion channels which lyse the cell. Distant homologues are found in mammals and slime molds. Its synthesis is induced by interleukin 2, and it exhibits antibacterial, antifungal, and antitumor activities. These amoebapore homologues have many properties in common including membrane binding and stability.