Ion effects on minimally hydrated polymers: hydrogen bond populations and dynamics.

Compared to bulk water, the effect of ions in confined environments or heterogeneous aqueous solutions is less understood. In this study, we characterize the influence of ions on hydrogen bond populations and dynamics within minimally hydrated polyethylene glycol diacrylate (PEGDA) solutions using Fourier-transform infrared (FTIR) and two-dimensional infrared (2D IR) spectroscopies. We demonstrate that hydrogen bond populations and lifetimes are directly related to ion size and hydration levels within the polymer matrix.

Lanmodulin's EF 2-3 Domain: Insights from Infrared Spectroscopy and Simulations.

Lanmodulins are small, ∼110-residue proteins with four EF-hand motifs that demonstrate a picomolar affinity for lanthanide ions, making them efficient in the recovery and separation of these technologically important metals. In this study, we examine the thermodynamic and structural complexities of lanthanide ion binding to a 41-residue domain, EF 2-3, that constitutes the two highest-affinity metal-binding sites in the lanmodulin protein from . Using a combination of circular dichroism (CD) spectroscopy, isothermal titration calorimetry (ITC), two-dimensional infrared (2D IR) spectroscopy, and molecular dynamics (MD) simulations, we characterize the metal binding capabilities of EF 2-3.