At the molecular level, all biological interactions are controlled by atoms located on the surface of macromolecular structures. The contacts between protein molecules and their surrounding water, determine the specificity and intensity of the interactions. Our scientific interest is at this atomistic level, looking at reactions that take place within the picosecond to nanosecond time frame over distances measured in Ǻ units.
The experimental system used in the Laser Laboratory for Fast Reactions (active since 1979) employed photo-excitation of photo acid molecules driving a sub-nanosecond acidification of the solution. The observations consisted of fast (microsecond) and ultra-fast (picoseconds) fluorescence and absorbance transitions, which were analyzed through integration of differential rate equations. These measurements were applied for probing defined spaces like the active site of proteins, the inter-membrane space in multi-lamellar bodies, the inner aqueous body of a reversed micelles and the solvation layer of protein. Since 2005, the main line of the research is detailed understanding of molecular events at atomic resolution using Molecular Dynamics techniques coupled with experimental measurement. These lines of research are exemplified by the following research topics and the resulting publications.
1) Properties of water molecules at the interface of proteins and membranes, with an emphasis on MRI imaging of lipids in water. Collaboration with Dr. Aviv Mezer, Safra Center for Brain Sciences. Hebrew University, Jerusalem.
2) Mechanism of ion passage through channelrhodopsin. Collaboration with Prof. E. Bamberg. MPI for Biophysics Frankfurt, Germany.
3) Interaction of ions with proteins, with emphasize on the difference between the crystal s and solution structures. Collaboration with Dr. Yossi Tsfadia Life sciences Tel Aviv University.
