In situ surface adsorption of the protein C hordein using atomic force microscopy

The surface adsorption of the rodlike protein C hordein has been directly imaged in the earliest stages of the process using atomic force microscopy. In a good solvent, 100 mM acetic acid, surface adsorption is marginally favored over desorption. However, a slight reduction in the concentration of the acetic acid leads to a marked increase in surface adsorption. The free surface is progressively covered to a single molecule thickness, with the molecule lying flat on the surface. Comparable in situ experiments on a hydrophobic surface, graphite, show that the protein-protein interaction dominates the surface adsorption on the hydrophilic surface.