Chemists Crack Secrets of Mussels' Super Glue

By Roland Piquepaille

As you can see below, this super glue is not terribly attractive to look at. Here is this mussel glue, as imaged by a scanning electron microscope at a magnification of 25,000X (Credit: Debby Sherman and Jonathan Wilker, Purdue University, NSF).

Other large images are available on this NSF page.

Here are some details about this discovery.

Researchers have discovered that iron in seawater is the key binding agent in the super-strong glues of the common blue mussel, Mytilus edulis. This is the first time researchers have determined that a metal such as iron is critical to forming an amorphous, biological material.

In addition to using the knowledge to develop safer alternatives for surgical and household glues, the researchers are looking at how to combat the glue to prevent damage to shipping vessels and the accidental transport of invasive species, such as the zebra mussel that has ravaged the midwestern United States.

Jonathan Wilker, Mary Sever and their colleagues at Purdue University present their work in the January 12 issue of Angewandte Chemie under the name "Metal-Mediated Cross-Linking in the Generation of a Marine-Mussel Adhesive."

En route to crafting synthetic versions of the glue, the researchers discovered that bivalves extract the metal iron from the surrounding seawater and use it to join proteins together, linking the fibrous molecules into a strong, adhesive mesh. The 800 mussels in Wilker's laboratory have an uncanny ability to stick to almost anything, even Teflon®.

Here is a mussel adhering to a sheet of poly(tetrafluoroethylene) (Teflon) (Credit: Wilker Group at Purdue University).

Now, the researchers want to know if such a creation of a protein through the use of metal is a common phenomenon.

"We are curious as to whether or not this newly discovered, metal- mediated protein cross-linking mechanism of material formation is a prevalent theme in biology. We will be exploring systems such as barnacle cement, kelp glue and oyster cement to see how other biomaterials are produced," says Wilker.

So, the next time you'll buy some superglue, you might read "grown from mussels" on the label.

Source: National Science Foundation, January 12, 2004, via EurekAlert!