Water structuring and collagen adsorption at hydrophilic and hydrophobic silicon surfaces

Daniel J. Cole,¹ Mike C. Payne,¹ Lucio Colombi Ciacchi^2,3

¹Theory of Condensed Matter Group, Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, UK
⁴Hybrid Materials Interfaces Group, Faculty of Production Engineering and Bremen Centre for Computational Materials Science, University of Bremen, 28359 Bremen, Germany
⁵Fraunhofer Institut für Fertigungstechnik und Angewandte Materialforschung IFAM, Wiener Str. 12, 28359 Bremen, Germany

The adsorption of a collagen fragment on both a hydrophobic, hydrogen-terminated and a hydrophilic, natively oxidised Si surface is investigated using all-atom molecular dynamics. While favourable direct protein-surface interactions via localised contact points characterise adhesion to the hydrophilic surface, evenly spread surface/molecule contacts and stabilisation of the helical structure occurs upon adsorption on the hydrophobic surface. In the latter case, we find that adhesion is accompanied by a mutual fit between the hydrophilic/hydrophobic pattern within the protein and the layered water structure at the solid/liquid interface, which may provide an additional driving force to the classic hydrophobic effect.

Phys. Chem. Chem. Phys. 11, 11395 (2009)