The chemical basis for how mussels glue themselves onto rocks and other surfaces is reported in a study published online this week in Nature Chemical Biology.
Mussels and other sticky sea creatures serve as a source of inspiration for biomaterials researchers, as their ability to attach to surfaces is unparalleled by any manmade glues. Mussels are known to use a modified tyrosine amino acid, DOPA, as a key ingredient in their adhesive abilities, but the specific role of this amino acid remains murky. Part of the challenge of elucidating this question comes from the very success of the residue, as scientists who study these proteins often complain that the proteins stick to whatever surface is near, limiting experimental tests.
Herbert Waite, Jacob Israelachvili and colleagues have directly examined these proteins as they are secreted from mussels as well as in purified form, and find that two proteins, mfp-3 and mfp-6, work in tandem to achieve the strong interaction. Mfp-6 maintains the DOPA residues within mfp-3 in a reduced, electron-rich form that maximizes their stickiness.