Understanding the adsorption of proteins onto materials surfaces is a major challenge in the design of biomaterials for medical applications and in the creation of nanostructured materials from protein building blocks. As the behaviour of proteins nears surfaces depends on the surface chemistry and structure, along with the protein sequence, a microscopic understanding of the protein adsorption process requires insight into the interplay between these different effects. Knowledge of how the nanoscale surface structure affects protein adsorption is in particular lacking.
In this presentation recent work using molecular dynamics simulation to investigate the effect of surface properties on protein conformation. Simulation of model peptides (LKpeptides) on nanostructured surfaces, consisting of alternating hydrophilic and hydrophobic stripes are used to investigate the role of surface structure on protein adsorption. The strongest adsorption is found for surfaces with larger hydrophobic regions as the peptides can minimise unfavourable contacts with hydrophilic regions of the surface. Changes to the conformational entropy of the peptides during adsorption are shown to play an important role in controlling the adsorption strength, with differences between the peptides appearing for narrow stripes. The role of surface hydrophobicity on the conformations of an intrinsically disordered protein, islet amyloid polypeptide (IAPP), is also investigated. The hydrophobic surface tends to make the protein more structured compared to hydrophilic surfaces and bulk solution. This information may be used to understand how the adsorption of proteins is related to the surface structure, allowing for control over biocompatibility and anti-fouling behaviour, and control over the formation of protein nanostructures on surfaces.