Biosynthesis of Melittin, a Toxic Peptide from Bee Venom

The biosynthesis of melittin, the main toxin of bee venom, was studied in vivo by feeding radioactive amino acids to honey bees. Extracts from venom glands were analyzed for the presence of labelled melittin and other components. Radioactivity was first incorporated into another peptide which is considered to be a precursor of melittin. This conclusion is based on the observed labelling kinetics demonstrating the transient formation of this peptide. Furthermore, the structural similarity between melittin and this component could be established. Evidence is presented showing that it differs from melittin at the amino end. The precusor peptide could not be detected in the ejected venom.