Adhesives that work underwater built from parts of proteins

Dmitry Lyakhov via Flickr

Adhesives that can form bonds underwater would be useful for many biomedical applications, yet few synthetic adhesives exist today. In the last decade, researchers have begun to look to the sea to investigate the organisms—mussels, barnacles, algae, and others—that naturally secrete durable underwater adhesives. Recently, scientists have successfully developed adhesives that are able to mimic their biological counterparts.

There are two natural protein systems that have been widely investigated thus far. One uses a chemical called 3,4-dihydroxyphenylalanine (DOPA) that links proteins together—we’ll call this the sticky part. The other relies on an amyloid structure, a flat assembly of proteins that tends to form dense fibers. In this work, investigators aimed to combine the sticky bit and the fibers to produce a next generation of bio-inspired adhesives. (They tested two sticky proteins—Mfp3 and Mfp5, which mimic DOPA-based mussel adhesive proteins—and the amyloid protein, CsgA.)

The authors used computer modeling to check whether the sticky parts could be merged with the fibrous one. They found that neither protein disrupted the other—it was possible to create a single molecule that combined both of their binding properties. Simulations also showed that these hybrid proteins spontaneously formed fibers, which suggests that this dual system could in fact be used to form adhesive materials. These fibers were held together by stacking of the amyloid core and adhesion from the sticky domains.