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Download fileProbing Ion/Molecule Interactions in Aqueous Solutions with Vibrational Energy Transfer
journal contribution
posted on 2016-02-20, 09:11 authored by Jiebo Li, Hongtao Bian, Xiewen Wen, Hailong Chen, Kaijun Yuan, Junrong ZhengInteractions between model molecules representing building
blocks
of proteins and the thiocyanate anion, a strong protein denaturant
agent, were investigated in aqueous solutions with intermolecular
vibrational energy exchange methods. It was found that thiocyanate
anions are able to bind to the charged ammonium groups of amino acids
in aqueous solutions. The interactions between thiocyanate anions
and the amide groups were also observed. The binding affinity between
the thiocyanate anion and the charged amino acid residues is about
20 times larger than that between water molecules and the amino acids
and about 5–10 times larger than that between the thiocyanate
anion and the neutral backbone amide groups. The series of experiments
also demonstrates that the chemical nature, rather than the macroscopic
dielectric constant, of the ions and molecules plays a critical role
in ion/molecule interactions in aqueous solutions.