posted on 2021-09-22, 22:03authored byStefan Rauwolf, Saientan Bag, Rodrigo Rouqueiro, Sebastian Patrick Schwaminger, Ana Cristina Dias-Cabral, Sonja Berensmeier, Wolfgang Wenzel
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.