Interfacial Mussel Proteins Characterization with the Surface Forces Apparatus

Abstract

The biomaterial that mussels produce to fix themselves to their substrate has become a model system for gleaming insights into effective underwater adhesion. These superficially simple animals are capable of fastening robust organic attachments to chemically diverse substrates such as ceramics, metal oxides, polymers and silicate clays. Proteins from this adhesive material have been purified and characterized resulting in a family of molecules with unusual charges, compositions and post-transnational modifications. One of these modifications, dihydroxyphenylalanine (DOPA) as gained traction for being found in a multitude of animal adhesive systems as well as having been shown to have impressive work of adhesion values in simple systems. Proteins from the mussel attachment plaque that are simultaneously found at the interface of the substrate and contain unusually high DOPA content were characterized by the Surfaces Forces Apparatus. This instrument allows for interactions between surfaces and deposited thin films to be measured. The force distance profiles calculated are sensitive to angstrom resolution and pN forces.In this talk the results of characterizing interfacial mussel foot proteins by with the surfaces forces apparatus will be discussed. The effects on adhesion from solution conditions- especially with regard to pH, protein-protein interactions, effects of protein oxidation and reduction, as well as the potential utility of borate protection are shown in a quantitative way.