Melittin is a small protein that is the principal cytotoxic component of venom of the honey bee, A. mellifera. Structurally, melittin consists of two α-helical segments forming a bent rod, with hydrophilic residues on the convex side and hydrophobic sites on the concave side. This allows melittin molecules to assemble as tetramers on membrane surfaces and form pores, resulting in cell death. Bee venom is also known to stimulate phospholipase A2 (PLA2) activity, and this may be linked to melittin-mediated pore production as well as the presence of low molecular weight PLA2 enzymes in the venom. Melittin also has antimicrobial properties, which, combined with its cytolytic properties, extends its potential for therapeutic applications.
