The molecular weight distribution of the components of giant hornet (Vespa orientalis) venom was studied, using gel-filtration on a column with Sephadex G-50. The effects of the venom and its constituent fractions on the permeability and stability of artificial bilayer phospholipid membranes, potassium ions release from the erythrocytes and mitochondrial oxidative phosphorylation parameters, as well as on the activity and stability of polyenzymic systems of the mitochondrial respiratroy chain, were studied. The data obtained suggest that the high molecular weight fractions contain phospholipases, whose activities are much higher than those of presently known venoms. Despite the fact that the hemolytic effect is typical for two low molecular weight fractions, no fractions possessing high activity of bee venom of the melitin type were found.
