Synthesis and characterization of cell-adhesive silk-like proteins constructed from the sequences of Anaphe silk fibroin and fibronectin.

New silk-like recombinant proteins, [(AAG)(6)ASTGRGDSPAAS](n) and [(AG)(9)ASTGRGDSPAAS](n), with high cell adhesive activities were designed and produced from E. coli. These are recombinant proteins with characteristic sequences from the silk fibroin of a wild silkworm, Anaphe , and the cell adhesive region, including the sequence RGD derived from fibronectin. They showed higher cell adhesion activity than the parent protein, Anaphe silk fibroin without the RGD sequence. In addition, the activities were very similar to that of collagen, which acted as a positive control. Thus, it is demonstrated that the primary structure of Anaphe silk fibroin, which is composed largely of alanine and glycine residues, can be used as a platform for the basic structures of silk-like cell adhesive proteins. The structural characterization of the silk-like recombinant proteins was performed with (13)C CP/MAS NMR.