Research objectives and content
Objective: The migration of ions through membranes in biological cells is of prime importance in life processes, and yet information regarding the various mechanisms involved has been deduced without a knowledge of the structure and dynamics of the ionophores and ion channels, embedded within the membranes. In recent years several surface analytical tools have emerged with the assistance of which one may obtain structural information concerning the arrangement of molecules on various interfaces. Such methods have been applied for probing the structure of Langmuir monolayers and phase transitions of these architectures at the air-liquid interface (via grazing incidence synchrotron X-ray diffraction, X-ray reflectivity, reflectance infra-red spectroscopy) and after transfer to solid support (via local probe techniques, transmission electron microscopy, etc.). In this project we plan to design and analyze model systems of membranes at interfaces and probe the structure, and hopefully ion transport properties, of ion channel molecules and ionophores incorporated within these artificial "membranes". The ion transport molecule we shall focus on valinomycin, a naturally occurring ionophore, as well as synthetic ion-channel molecules such as the cyclic peptides prepared by Ghadiri et al (1,2)
Training content: The training at the Weizmann institute will enable L. Nedelmann to work independently on molecular architecture at surfaces and interfaces. For this purpose, he will learn various experimental techniques (Languir-Blodgett processes, GID) and be provided with the relevant (bio)chemical and crystallographical background.