Negligible Isotopic Effect on Dissociation of Hydrogen Bonds

Li-Ion solvation in propylene carbonate electrolytes determined by molecular rotational measurements

We report the solvation structure of Li⁺ in LiPF₆–PC solutions using ultrafast vibrational spectroscopy. The results illustrate the salt concentration-dependent solvation structures, in accordance with the variation of ion conductivity.

Site-Specific Hydrogen Exchange in a Membrane Environment Analyzed by Infrared Spectroscopy

Hydrogen exchange is a powerful method to examine macromolecules. In membrane proteins, exchange can distinguish between solvent-accessible and -inaccessible residues due to shielding by the hydrophobic environment of the lipid bilayer. Herein, rather than examining which residues undergo hydrogen exchange, we employ a protocol that enables the full deuteration of all polar hydrogens in a membrane protein. We then measure the impact of hydrogen exchange on the shift of the amide I vibrational mode of individually labeled sites. The results enable us to correlate polarity with vibrational shifts, thereby providing a powerful tool to examine specific locations within a membrane protein in its native membrane environment.