Regensburg 2013 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 87: Focussed Session: Solid-liquid Interfaces III
O 87.8: Vortrag
Freitag, 15. März 2013, 12:15–12:30, H31
Probing the interaction of ice nucleating proteins with water molecules using SFG spectroscopy — •Ravindra Pandey1, Michael Schleeger1, Janine Fröhlich2, Ulrich Pöschl2, Mischa Bonn1, and Tobias Weidner1 — 1Max Planck Institute of Polymer Research, Mainz, Germany — 2Max Planck Institute for Chemistry, Mainz, Germany
Specific Bacteria can cause crop frost damage by using ice-nucleating (IN) proteins anchored to their outer cell surfaces. IN proteins mimic the structure of ice surfaces and, thus, promote the growth of ice crystals by acting as efficient templates for ice nucleation. Frost damage caused by ice crystals facilitates bacterial invasion of affected plants. IN proteins not only play an important role for agriculture - airborne proteins can also promote ice formation in the atmosphere and may change precipitations patterns. The molecular mechanisms by which IN proteins interact with water molecules have not yet been resolved. We have investigated the interaction of IN proteins with water molecules using sum frequency generation (SFG) vibrational spectroscopy. When cooling the sample from room temperature to freezing, we found that the order of water molecules in contact with IN proteins is suddenly increased for temperatures near freezing (4-5°C). This effect was not observed for liquid water surfaces without the protein. The data also indicates a change of protein structure near the nucleation temperature.