]A biomimetic approach inspired by

]A biomimetic approach inspired by mussel adhesive activity has recently been developed as astrategyforthesurfacemodificationofmetalsandceramics with biological materials. Considering that the underwater adhesive protein secreted by mussels contains3,4-dihydrox- yphenethylamine (DOPA) in its active site,[3]it is possible to incorporate proteins containing DOPA or one of its more simplified derivatives dopamine as a strategy for thesurface modification of metals and ceramics.[4]Although numerous DOPA-containing peptides and macromolecules have been reported,[5]the site-specific incorporation of DOPA into proteins,suchasgrowthfactors,ofwhichtertiarystructureare important for the signal transduction activity, have not been reported. It is important to incorporate DOPA without disturbing the tertiary structure and active site of proteins. If such a protein is prepared, it should play a much greater regulatoryroleincells,includinggeneexpressionforcellular growth and differentiation by binding on various materials. However, because DOPA is a non-canonical amino acid, it cannot be directly incorporated into a protein using conven- tional protein-engineering (recombinant DNA)techniques.