Experimental and computational examination of protein-surface interactions

Using a combination of experimental and computational approaches, the interaction between anastellin, a recombinant fragment of fibronectin, and representative biomaterial surfaces has been examined. The molecular interaction was directly quantified by atomic force microscope (AFM) based force spectroscopy, complemented by adsorption measurements using quartz crystal microbalance (QCM). It was found that the anastellin molecules facilitates a stronger adhesion on polyurethane films (72.0 pN nm-1) than on poly (methyl methacrylate) films (68.6 pN nm-1). This is consistent with the adsorption measurements of anastellin on the two polymeric surfaces, observed by QCM. Molecular dynamics simulations of the behaviour of anastellin on polyurethane in water and sodium chloride solutions were performed to rationalise the experimental data, and show that anastellin is capable of rapid adsorption to PU while its secondary structure is stable upon adsorption in water.