Fig 1.
The geometries of the TiO2 polymorphs that were used for the biomolecular surface adsorption simulations.
Color code: oxygen, red; titanium, pink. Visualization was performed using VMD 1.9.3 program in CPK representation.
Fig 2.
The radial distribution function (RDF) of oxygen to oxygen and titanium to titanium distances in the amorphous TiO2 structure.
Fig 3.
Biomolecules included in the MD simulations.
Color code: oxygen, red; nitrogen, dark blue; carbon, cyanide blue; hydrogen, white-gray. Visualization was performed using VMD 1.9.3 in CPK representation.
Fig 4.
The distance between the biomolecules and the TiO2 surfaces over time.
Fig 5.
Adsorption time ratio (a) full simulation time, (b) first 250 ns, and (c) second 250 ns for the studied peptides on the surfaces of the three polymorphic structures of TiO2.
Adsorption distance was defined as 0.5 nm measured from the surface of TiO2.
Fig 6.
Distribution of the (a) RGD and (c) LGD tripeptide-TiO2 surface distances averaged for the whole simulation time. Note, that results are shown up to 0.5 nm only and molecules may spend considerable amount of time also in unbound state, where the distance is larger than this value. Snapshot (b) of RGD bound to Rutile at 300 ns and (d) of LGD bound to rutile at 500 ns. Representation of (b) and (d): peptide CPK, rutile VDW, water molecules CPK, only surface water molecules are shown for clear visualization. Images were made with VMD 1.9.4.
Table 1.
The maximum values of the pulling forces on the polymorphic TiO2 surfaces of the investigated peptides.
The binding energy was estimated from the force-distance diagram by numerical integration of the curves in the adsorption distance interval.
Fig 7.
A representative force-distance diagram showing the pull force as a function of the molecule distance from the TiO2 surface.
Fig 8.
Binding energy as a function of maximum force.
Both values were determined from the pulling simulation diagrams. The linear fit shows the correlation between these quantities.
Fig 9.
(a) Adsorption time ratio and (b) binding energies averaged for the three TiO2 surface types for each biomolecule with standard deviations.