Insights on Alanine and Arginine Binding to Silica with Atomic Resolution

Interactions of biomolecules with inorganic oxide surfaces such as silica in aqueous solutions are of profound interest in various research fields, including chemistry, biotechnology, and medicine. While there is a general understanding of the dominating electrostatic interactions, the binding mechanism is still not fully understood. Here, chromatographic zonal elution and flow microcalorimetry experiments were combined with molecular dynamic simulations to describe the interaction of different capped amino acids with the silica surface. We demonstrate that ion pairing is the dominant electrostatic interaction. Surprisingly, the interaction strength is more dependent on the repulsive carboxy group than on the attracting amino group. These findings are essential for conducting experimental and simulative studies on amino acids when transferring the results to biomolecule-surface interactions.

Automated summary

This study combines chromatographic zonal elution, flow microcalorimetry experiments, and molecular dynamics simulations to investigate the interaction mechanism between amino acids and silica surfaces. It found that ion pairing is the dominant electrostatic interaction, with the interaction strength depending more on the repulsive carboxy group than the attracting amino group.