Learning from the Pieces: The Adhesion of Mussel-Inspired Peptides

Abstract

The 3,4-dihydroxyphenylalanine (Dopa)-containing proteins of mussels provide attractive design paradigms for engineering synthetic polymers as wet adhesives and coatings. Although the role of Dopa on mussel adhesion has been carefully studied, a full picture of the whole binding mechanism of mussel proteins is still unclear due to the complexity of the protein molecules and molecular processes involved. We designed three short peptides based on mussel foot protein-5 (Mfp-5), and converted the tyrosine residues to Dopa through in vitro enzymatic modification. The binding mechanisms of the three peptides were tested using a surface forces apparatus. Our results show that in addition to Dopa-specific binding, non-specific electrostatic interactions also contribute to the binding mechanisms of all three peptides to mica surfaces. Our measurements provide important new details for understanding the binding mechanism of mussel foot proteins that can be utilized in designing Dopa containing adhesives. Taking short sequences from the mussel adhesive proteins also suggests an effective method for designing better mussel inspired adhesives.