January 3, 2007
For those who live near large bodies of water, the sight of mussels attached to shoreline rocks, waves rhythmically lapping over them, is as familiar as the sunrise. But underpinning this everyday sight is a remarkable - and often overlooked - feat of biochemical engineering. Mussels can adhere to virtually any surface - wet or dry, organic or inorganic - and remain in place despite the surge of the sea, the whipping of the winds, or just about any other sheer force that nature throws their way. This all-purpose adhesiveness intrigued an NIDCR grantee many years ago as one of nature's best guides to design better dental and medical bioadhesives. Since then, the grantee has discovered a fascinating trove of novel bioadhesive proteins in mussels and, in the November issue of the journal Biochemistry, he reports another unique find. It is called mcfp-4, a histidine-rich, metal-binding protein that mussels rely on at load bearing junctions. In this case, the junction being the merging of the splayed ends of the mussel's tethering byssal threads and its adhesive pad, a convergence the authors describe "not unlike a tree deeply rooted in the earth." As the authors note, "Synthetic analogues of the consensus sequences of several histidine-rich proteins have unexpectedly provided effective metal ion binding functionalities for scaffolds used in the fabrication of nanowires and nanolithography. Given its involvement in an evolved load-bearing structure and remarkable capacity for copper binding, mcfp-4 may help to inspire a new generation of metallopolymers."