Toward development of nano-materials composed of artificial proteins and nano-carbons

Fusion materials composed of proteins and nanostructured carbons have a significant potential in various fields including pharmaceuticals, semiconductor technology and material engineering. For example, the internal space of single-wall carbon nanohorns (SWNHs) can be used as a new tool for a drug delivery system (DDS) or a noninvasive imaging system in which proteins would endow biocompatibility and organ specificities to the nanostructured carbons. To translate these potential capacities of the SWNHs into practical applications in the medical area, it is necessary to create artificial proteins that specifically bind to SWNHs and carry the desired biological function(s). In this presentation, we will describe our efforts to develop protein and nano-carbon hybrid materials using our newly established MolCraft methodology. With MolCraft, a single microgene is first designed so that a number of functional motifs would be coded by different coding frames, and then the designer microgene is polymerized in a head-to-tail manner to create repetitious artificial genes. The resultant microgene polymers produce proteins that are combinatorial polymers of embedded functional motifs, among which functional clones are selected. As the first step in the construction of fusion materials composed of protein and SWNHs, we have selected peptide motif, from peptide-display phage libraries that specifically recognize SWNHs. By embedding the determined motif into a microgene, several artificial proteins have been created by MolCraft.