Noam Agmon: "Proton Mobility in Water and Proteins"
von 13:15 bis 14:00
|Wo||FRIAS Seminar Room, Albertstr. 19, 79104 Freiburg|
Open to University employees
Department of Physical Chemistry, Hebrew University, Jerusalem, Israel
Proton Mobility in Water and Proteins
Proton mobility is important for reactions in solution and biological systems. Recent studies reveal a range of mechanisms, more stochastic in bulk liquid water, concerted multi-proton hopping along short water-wires connecting acid and base in solution, and a "proton collecting antenna" in the green fluorescent protein (GFP).
In room temperature bulk water, MS-EVB simulations revealed a dynamically distorted hydronium (H3O+) undergoing the "special pair dance". Eventually a protonated dimer (H5O2+ cation) is formed, allowing proton hopping between these two water molecules. The IR band of this "proton-transfer mode" has been identified using a "clusters-in-liquid" approach.
A high resolution X-ray structure of GFP revealed an internal wire connecting its chromophore to a putative "proton collecting antenna" on a negative surface patch. It could possibly be recruiting a proton from solution to replenish that which escaped following photo-excitation.