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Download fileInvestigating the Conformation of Surface-Adsorbed Proteins with Standing-Wave X‑ray Fluorescence
journal contribution
posted on 2021-11-23, 19:03 authored by Ernesto Scoppola, Georgi G. Gochev, Jakub Drnec, Linus Pithan, Dmitri Novikov, Emanuel SchneckProtein
adsorption to surfaces is at the heart of numerous technological
and bioanalytical applications, but sometimes, it is also associated
with medical risks. To deepen our insights into processes involving
layers of surface-adsorbed proteins, high-resolution structural information
is essential. Here, we use standing-wave X-ray fluorescence (SWXF)
in combination with an optimized liquid-cell setup to investigate
the underwater conformation of the random-coiled phosphoprotein β-casein
adsorbed to hydrophilic and hydrophobized solid surfaces. The orientation
of the protein, as determined through the distributions of sulfur
and phosphorus, is found to be sensitive to the chemical nature of
the substrate. While no preferred orientations are observed on hydrophobized
surfaces, on hydrophilic Al oxide, β-casein is adsorbed as a
diblock copolymer with the phosphorylated domain I attached to the
surface. Our results demonstrate that targeting biologically relevant
chemical elements with SWXF enables a detailed investigation of biomolecular
layers under near-physiological conditions.
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resolution structural informationprocesses involving layershydrophilic al oxidecoiled phosphoprotein βhydrophobized solid surfaceshydrophobized surfacesbiomolecular layerswave xresults demonstrateray fluorescencepreferred orientationsphysiological conditionsphosphorylated domainoptimized liquidnumerous technologicalmedical risksdiblock copolymerdetailed investigationchemical naturecell setupbioanalytical applicationsalso associated