Interaction of the mosquitocidal crystal proteins from bacillus thuringiensis isreaelensis with phospholipid vesicles

ABSTRACT

The 125-130 KDa mosquitocidal proteins of the Bacillus thuringiensis israelensis delta-endotoxin were purified, activated in vitro and their interaction with phospholipid Iiposomes studied. The crystal proteins were found to cause a rapid increase in the light scattering of liposome suspensions, which reflects a morphological change in the lipid bilayer. When liposomes loaded with radioactive markers were incubated with activated crystal proteins a relatively rapid release of more than 60% of the trapped markers occurred. It is suggested that segments of the toxin molecules may become partitioned in the lipid bilayers to cause the formation of leakage pores