Understanding protein-surface interactions is crucial to solid-state biomedical applications whose functionality is directly correlated with the precise control of the adsorption configuration, surface packing, loading density, and bioactivity of protein molecules. Due to the small dimensions and highly amphiphilic nature of proteins, investigation of protein adsorption performed on nanoscale topology can shed light on subprotein-level interaction preferences. We examine the adsorption and assembly behavior of a highly elongated protein, fibrinogen, on both chemically uniform and varying surfaces. By focusing on high resolution imaging of individual protein molecules whose configurations are influenced by protein-surface rather than protein-protein interactions, fibrinogen conformations characteristic to each surface are identified and statistically analyzed for structural similarities/differences in key protein domains. By exploiting polystyrene-block-polymethylmethacrylate (PS-b-PMMA) nanodomains whose repeat distance is commensurate with the length of the individual protein, we determine that fibrinogen exhibits a more neutral tendency for interaction with both PS and PMMA blocks relative to the case of common globular proteins. Factors affecting fibrinogen-polymer interactions are discussed in terms of hydrophobic and electrostatic interactions. In addition, assembly and packing attributes of fibrinogen are determined at different loading conditions. Primary orientations of fibrinogen and its rearrangements with respect to the underlying diblock nanodomains associated with different surface coverage are explained by pertinent protein interaction mechanisms.

Distinct Adsorption Configurations and Self-assembly characteristics of elongated proteins on chemically uniform and alternating surfaces

249th National Meeting (2015)

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