The purpose of this master thesis was to obtain aegerolysin proteins OlyA6, PlyA2 and EryA, and their MACPF-partnering protein PlyB. Combinations of the aegerolysins with PlyB are known to form non-selective transmembrane pores on membranes of suitable lipid composition (ceramide phosphoethanolamine or spingomyelin in combination with cholesterol). EryA/PlyB is selective for combination of ceramide phosphoethanolamine and cholesterol, while OlyA6/PlyB and PlyA2/PlyB can also perforate membranes composed of sphingomyelin and cholesterol. Since ceramide phosphoethanolamine, together with cholesterol, is present in certain insect membranes in high enough concentrations for activity of aegerolysin complexes, we decided to evaluate their toxicity on spotted wing Drosophila (Drosophila suzukii), English grain aphid nymphs (Sitobion avenae), mealworm larvae (Tenebrio molitor) and greater wax moth larvae (Galleria mellonella). Results showed that none of the tested animals are susceptible to aegerolysin-based complexes. The reasons might include a (1) lack of ceramide phosphoethanolamine in membranes of these animals since there is no direct evidence of its presence in these particular insects, (2) proteolytic degradation of pore-forming proteins by gut enzymes, (3) unsuitable pH in guts for activity of aegerolysin complexes, (4) inaccessibility of appropriate lipid domains because of extracellular matrix or stereochemical obstructions or (5) absence of yet unknown coreceptor that is essential for definitive function of aegerolysins complexes in living systems.
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