抄録
Offer Organization: Japan Society for the Promotion of Science, System Name: Grants-in-Aid for Scientific Research, Category: Grant-in-Aid for Scientific Research (S), Fund Type: -, Overall Grant Amount: - (direct: 79700000, indirect: 23910000)
This research project aims to expand molecules like amino acids, nucleic acids and proteins constitute the protein biosynthesizing system to synthesize novel type of proteins with artificial functions. The final goal is to create synthetic microorganisms that live with 21 type of amino acids. During the 5 year we obtained the following results. (1) Some nonnatural amino acids were successfully charged onto a specific tRNA by the use of a peptide nucleic acid (PNA) that is complementary to the tRNA. The PNA-assisted aminoacylation mold be carried out in an E.coli in vitro protein biosynthesizing system to create a protein incorporated with the nonnatural amino add. (2) tRNAs and an elongation faint Tu. (EF-Tu) were expanded to bring large-sized nonnatural amino adds into E.col ribosome and subsequently to a protein. (3) An orthogonal set of aminoacyl tRNAsynthetase (ARS) and tRNA was screened to bring some nonnatural amino acids into proteins in living mammalian cells. (4) Finally these expanded molecular systems were introduced into mammalian cells and the synthesis of proteins containing nonnatural amino acids was detected, although its quantity was very small.
In the last year, an attempt was made to apply these techniques to attach fluorescent amino acids to peptides and proteins. The fluorescently labeled peptides were screened to dimmer those that bind to cancer cells or to cancer-cell specific proteins.