Genetically engineered calmodulin self-assembled on gold surface

In order to construct intelligent materials consisting of functional protei ns, the assembling techniques of proteins with retaining their functions ev en on a solid surfaces are required. Calmodulin, which expresses modulating function by conformation change with calcium binding, was selected as a mo del protein for molecular assembling. Calmodulin was genetically engineered for self-assembling on the gold surface with an oriented manner by introdu cing cysteine residues at the N-terminus of calmodulin. The engineered calm odulin retained Ca2+-responsive modulating function of enzyme activity as n ative calmodulin. Enzyme immunoassay and quartz crystal microbalance reveal ed that the engineered calmodulin was efficiently assembled on the gold sur face in an acidic buffer solution as compared with native calmodulin. Genet ic engineering is discussed to be effective on modifying proteins to be sel f-assembled on solid matrices.