Mussel Adhesive Proteins

Role of L-3,4-Dihydroxyphenylalanine in Mussel Adhesive Proteins, by Miaoer Yu, Jungyeon Hwang, and Timothy J. Deming, published in June 1999 by the Journal of the American Chemical Society, available at http://pubs.acs.org/doi/full/10.1021/ja990469y?&


The blue mussel, Mytilus edulis, anchors itself to rocks and other surfaces using structures called byssal threads. The threads produce an adhesive that is waterproof and incredibly strong. Isolating the compounds responsible for this adhesive property would allow it to be synthetically reproduced and used in numerous medical procedures where a strong adhesive is necessary.

Miaoer Yu, Jungyeon Hwang, and Timothy J. Deming worked with these mussel adhesive proteins, or MAPs. The biggest challenge in replicating the adhesive was isolating the particular protein responsible for its strength. They thought that a protein called L-3,4-dihydroxyphenylalanine, or DOPA, was responsible, but also suspected that other proteins might be involved, complicating the mechanism of adhesion. They isolated a variety of adhesive proteins and found that, while many different amino acids were present, DOPA levels were consistently high among all samples.

Yu, Hwang, and Deming developed a series of experiments to determine which proteins were responsible for the adhesive properties of MAPs. Preliminary research suggested DOPA was the protein common to all MAPs, so they tested DOPA copolymers containing different amino acids, looking for differences in adhesive strength. All copolymers tested formed strong, waterproof adhesive bonds. They concluded that DOPA was responsible for the adhesive properties of MAPs.

The article describing the results of this study was published ten years ago, but new applications of MAPs have been discovered more recently. Researchers at Northwestern University developed a coating for medical devices susceptible to clogs and build up of cells and proteins. The coating is two-sided: one side, a strong adhesive based on MAPs, sticks to the device, and the other side, a repellant, prevents unwanted build up. This could mean fewer clots and increased efficacy of implants ranging from stents to catheters. MAPs are also being studied as a possible gene delivery material to be used in gene therapy. This technology has the potential to reach across many different areas of medicine. A strong, nontoxic adhesive that can be used in biomedical procedures and devices with reliable results is invaluable to engineers as they develop new technologies.