The conformation of proteins is well-recognized as being
of paramount importance to their function in living
systems and synthetic bio-devices. We are interested in
the interaction of proteins with hydrophobic solid
surfaces. Does the protein change its structure upon
adsorption on the surface? What are the molecular-level
chemical features of the protein and surface that are
responsible for these changes? An increased
understanding of these questions is vital to ensure the
continued development of biomaterials such as implants and
biosensors. Our group tackles these questions using a
combination of experimental and theoretical
approaches. In general, these questions require an
investigation not only of the adsorbed molecule
structure, but also of the surrounding solvent
and surface characteristics of the solid surface.
adsorbed molecule structure
Hydrophobic surfaces are ubiquitous in medical implants,
biosensors, and chromatographic supports. The
natural conformation of proteins is such that their
hydrophobic residues are buried in their cores, suitable
for aqueous environments in vivo. When these
molecules encounter hydrophobic surfaces such as polymers,
they may alter their shape — often in an irreversible
manner — in order to maximize surface contain of their
hydrophobic residues. This may have a significant
impact on the function of the proteins.
Our group develops methods to probe the molecular-level
interactions that occur between the biomolecules, the
surface, and the interfacial solvent molecules. Among
these are experimental techniques such as nonlinear
vibrational spectroscopy and ellipsometery. We also
employ electronic structure calculations and molecular
dynamics simulations to complement and assist in the
interpretation of the spectra.
interfacial water structure
When water molecules find themselves adjacent to a solid
surface, they adopt a surprisingly well-ordered structure
that extends over several molecular dimensions into the
bulk water phase. This is a consequence of reduced
hydrogen-bonding opportunities next to a surface.
These ordered arrangements depend sensitively on the
surface and solution conditions, and are ultimately
responsible for the attraction and subsequent ordering of
other molecules at the solid-liquid interface. One
may consider that the structure proteins adopt at solid
surfaces is first in response to the local water
environment near the surface. Once biomolecules are
able to penetrate the first few water molecules, only then
are specific interactions with the surface realized.
Understanding interfacial solvent structure is therefore a
key aspect of biomolecule-surface interactions.
We employ many of the same experimental and computational
tools towards characterization water structure near a
variety of solid surfaces.
substrate surface structure
The detailed structure of the solid surface, including the
density and types of chemical functional groups present, is
critical to an understanding of the adsorbed molecular
structure. In the case of complex surfaces such as
polymers, the surface structure may be significantly
different from that in the bulk polymer phase.
© DK Hore, Department of Chemistry, University