| 1.Research Institution | Tokyo Institute of Technology | |
| 2.Research Area | Integrated Fields | |
| 3.Research Field | Production of Novel Useful Substances through Integration of Life Sciences and Chemistry | |
| 4.Term of Project | FY 1997 〜 FY 2001 | |
| 5.Project Number | 97I00301 | |
| 6.Title of Project | Chemical Approach to Creation of Artificial Nucleic Acids Having New Functions |
| Name | Institution,Department | Title of Position |
| Mitsuo, Sekine | Tokyo Institute of Technology, Graduate School of Bioscience and Biotechnology | Professor |
8.Core Members
| Names | Institution,Department | Title of Position |
| You, Kikuchi | Toyohashi University of Technology, Faculty of Engineering | Professor |
| Makoto, Komiyama | The University of Tokyo, Research Center for Advanced Science and Technology | Professor |
| Akira, Matsuda | Hokkaido University, Graduate School of Pharmaceutical Sciences | Professor |
9.Summary of Research Results
|
The aim of this project is to create useful artificial nucleic acid derivatives having a new function
which is designed by chemical approaches. During the past five years, the following representative
results from this project were obtained. To realize our purpose, we developed new efficient methods
for the synthesis of DNA without protection of base residues. As the result, we created a new
innovative method called "proton-block method", where the base parts are protected by a simple
proton and nearly 100% selective internucleotidic bond formation was achieved at the dimer level.
We also found the hitherto most selective method for the internucleotidic bond formation by use of a
new activator, i.e., N-hydroxybenzotriazole (HOBT). This reagent enables us to synthesize
oligonucleotides without N-phosphorylation. The synthesis of the 5'-terminal 4mer of U1 snRNA
having a unique trimethyl-G cap structure was successfully done by use of the solid phase synthesis
and used for isolation of 2,2,7-trimethylguanosine-cap binding proteins. Consequently, snurportin 1
was discovered as a TMG-cap carrier to nucleus from cytoplasm. The mechanism of nuclear
transport of U1snRNA was now elucidated by this study. We succeeded in synthesize a sterically
locked "bent structural motif" of UpU derivative, which was successfully incorporated into RNAs.
On the other hand, it was found that oligonucleotides having a sterically fixed linear UpU derivative
have considerably higher Tm values than unmodified oligonucleotides. This results suggest that
this type of modification could provide a very useful antisense DNA molecules. Incorporation of
2-thiouridine derivatives into RNAs resulted in precise recognition of the complementary base of A
without formation of mismatched base pair which has been a serious problem in gene diagnosis.
Other innovative research results, the following new nucleic acids were synthesized: N-aminoacyl
phosphoramidate derivatives as the most ideal analogs of aminoacyl adenylate, DNA oligomers
having 3'-3' terminal linkage capable of bind to DNA duplexes, artificial DNA molecules capable of
selective cleavage of target RNAs in specific positions. |
10.Key Words
(1)chemical synthesis of DNA、(2)N-acyl DNA、(3)nuclear Transport of U1snRNA
(4)hypermethylated cap structure、(5)bent DNA structure、(6)linear DNA structure
(7)2-thiouridine、(8)gene diagnosis、(9)antisense method