Exposure of nanomaterials (NMs) to
biological medium results in
their direct interaction with biomolecules and the formation of a
dynamic biomolecular layer known as the biomolecular corona. Despite
numerous published data on nano-biointeractions, the role of protein
glycosylation in the formation, characteristics, and fate of such
nano-biocomplexes has been almost completely neglected, although most
serum proteins are glycosylated. This study aimed to systematically
investigate the differences in interaction of metallic NPs with glycosylated
vs nonglycosylated transferrin. To reach this aim, we compared interaction
mechanisms between differently sized, shaped, and surface-functionalized
silver NMs and gold NMs to commercially available human transferrin
(TRF), a glycosylated protein, and to its nonglycosylated recombinant
form (ngTRF). Bovine serum albumin (BSA) was also included in the
study for comparative purposes. Characterization of NMs was performed
using transmission electron microscopy and dynamic and electrophoretic
light scattering techniques. Fluorescence quenching and circular dichroism
methods were used to evaluate protein binding constants on the nanosurface
and conformational changes after the protein–NM interactions,
respectively. Competitive binding of TRF, ngTRF, and BSA to the surface
of different NMs was evaluated by separating them after extraction
from protein corona by gel electrophoresis following quantification
with a commercial protein assay. The results showed that the binding
strength between NMs and transferrin and the changes in the secondary
protein structure largely depend not only on NM physicochemical properties
but also on the protein glycosylation status. Data gained by this
study highlight the relevance of protein glycosylation for all future
design, development, and efficacy and safety assessment of NMs.