Up to now, structural changes of the Bt-Cry toxins during molecular assembly of the membrane-surface bound pre-pore oligomers and the membrane-inserted protomer complex in lipid membranes still remain fully elusive. This project will therefore attempt further: (i) to establish 3D structure of the oligomeric pre-pore and the membrane-inserted protomer complex formed by the two closely related mosquito-larvicidal proteins, Cry4Aa and Cry4Ba toxins; (ii) to analyse structural changes during the molecular assembly of Cry4Aa or Cry4Ba protomers in lipid membranes: conformational differences between the water-soluble molecules and the membrane-penetrating protomeric forms as well as key residues involved in structural changes.
