Tuning the orientation of an antigen by adsorption onto nanostriped templates.
We investigate the adsorption of a globular protein (P.69 pertactin, also known as antigen 69k) on protein-repellent hydrophilic substrates bearing regularly spaced hydrophobic nanostripes, for stripe widths comprised between 20 and 160 nm. Protein adsorption is shown to be remarkably well-controlled by the templating substrates, with a near-to-perfect reproduction of stripes by the protein monolayer down to 20 nm width, except for a 5-10 nm broadening. However, whereas the ellipsoidal protein forms a dense monolayer with random orientation of its long axis for large stripe widths, it adsorbs in a predominantly side-on (flat-on) orientation for stripe widths below 50 nm, due to the easier reorientation (interfacial relaxation) of the proteins adsorbed at the edges of the stripes, which experience a decreased lateral interaction. These results show that protein confinement in regions of a size similar to their dimensions can be used to tune their orientation, which may be of interest for applications in high-density sensor devices.
Pallandre
Antoine
A
Unité de Physique et de Chimie des Hauts Polymères (POLY) and Research Center in Micro- and Nanoscopic Materials and Electronic Devices (CeRMiN), Université catholique de Louvain, Place Croix du Sud, 1, B-1348 Louvain-la-Neuve, Belgium.
De Meersman
Benoit
B
Blondeau
Françoise
F
Nysten
Bernard
B
Jonas
Alain M
AM
D000327:Adsorption; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry*; D005027:Ethylene Oxide / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D018625:Microscopy, Atomic Force; D036103:Nanotechnology / Q000379:methods*; D010566:Virulence Factors, Bordetella / Q000737:chemistry*
D001425:Bacterial Outer Membrane Proteins; D010566:Virulence Factors, Bordetella; C068929:pertactin; D005027:Ethylene Oxide