Main toxin of bee venom with strong hemolytic activity and antimicrobial activity. It has enhancing effects on bee venom phospholipase A2 activity. This amphipathic toxin binds to negatively charged membrane surface and forms pore by inserting into lipid bilayers inducing the leakage of ions and molecules and the enhancement of permeability that ultimately leads to cell lysis. It acts as a voltage-gated pore with higher selectivity for anions over cations. The ion conductance has been shown to be voltage-dependent. Self-association of melittin in membranes is promoted by high ionic strength, but not by the presence of negatively charged lipids. In vivo, intradermal injection into healthy human volunteers produce sharp pain sensation and an inflammatory response. It produces pain by activating primary nociceptor cells directly and indirectly due to its ability to activate plasma membrane phospholipase A2 and its pore-forming activity (By similarity). Shows lower cytotoxicity when tested on E.coli and cancer cell lines than melittin, as well as lower anti-inflammatory properties and lower properties to interact to small unilamellar liposomes (PubMed:24512991). Monomer (in solution and for integration into membranes), homotetramer (in solution and potentially as a toroidal pore in membranes), and potenially homomultimer (as a toroidal pore in membranes). Alpha-helical peptides form toroidal pores in the prey. Expressed by the venom gland. Belongs to the melittin family.