Observing the Hydration Layer of Trehalose with a Linked Molecular Terahertz Probe.
The terahertz (THz) absorption bands of biomolecular hydration layers are generally swamped by absorption from bulk water. Using the disaccharide trehalose, we show that this limitation can be overcome by attaching a molecular probe. By time-resolving the fluorescence shift of the probe, a local THz spectrum is obtained. From the dependence on temperature and H2O/D2O exchange, it is concluded that the trehalose hydration layer is being observed. The region of dynamic water perturbation by the disaccharide encompasses the probe and is therefore larger than the first two solvation layers.
Department of Chemistry, Humboldt Universität zu Berlin, Brook-Taylor-Strasse 2, D-12489 Berlin, Germany.
Mohsen
M
Sajadi
Department of Chemistry, Humboldt Universität zu Berlin, Brook-Taylor-Strasse 2, D-12489 Berlin, Germany.
Falko
F
Berndt
Department of Chemistry, Humboldt Universität zu Berlin, Brook-Taylor-Strasse 2, D-12489 Berlin, Germany.
Celin
C
Richter
Department of Chemistry, Humboldt Universität zu Berlin, Brook-Taylor-Strasse 2, D-12489 Berlin, Germany.
Mario
M
Gerecke
Department of Chemistry, Humboldt Universität zu Berlin, Brook-Taylor-Strasse 2, D-12489 Berlin, Germany.
Rainer
R
Mahrwald
Department of Chemistry, Humboldt Universität zu Berlin, Brook-Taylor-Strasse 2, D-12489 Berlin, Germany.
Nikolaus P
NP
Ernsting
solvation; time-dependent Stokes shift; water dielectric dispersion