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Biomedical subjects

Masayuki Fujii

Publications and source records attributed to Masayuki Fujii.

28 records · Page 2Linked to original sources
PubMed2003

Antisense effects of DNA-peptide conjugates.

Antisense conjugate DNA covalently bound to functional amines, sugars or peptides such as nuclear localization signals (NLS), nuclear export signals (NES) and artificial amphiphilic alpha-helical and beta-sheet peptides were synthesized by solid phase fragment condensation (SPFC). Inhibitory effects on human telomerase of synthesized antisense conjugate DNAs were evaluated by TRAP assay. Antisense conjugate DNAs showed several times higher inhibitory effects on telomerase activity compared to native antisense DNA in cell lysis solutions. Antisense conjugate DNAs showed comparable or higher as same as inhibitory activity compared with antisense phosphorothioate DNA (S-DNA). Interestingly, antisense conjugate DNA showed much higher inhibition against telomerase activity with native antisense DNA or antisense phosphorothioate DNA in cellular system. We observed enhanced cellular uptake and positively controlled intracellular localization of conjugate DNAs by use of confocal fluorescent microscope.

Amino Acid Sequence↗
PubMed2003

Control of intracellular delivery and inhibition of genetic expression by DNA-peptide conjugates.

Various types of DNA-peptide conjugates were synthesized by solid phase fragment condensation (SPFC). DNA-LNS (nuclear localizing signal) peptide conjugate was proved to be delivered and localized into cellular nucleus and exhibited higher antisense inhibitory effect against telomerase than antisense phosphorothioate DNA. In contrast, DNAzymes conjugated with NES (nuclear export signal) peptide was shown to be taken up and localized in cytoplasm. Inhibitory effect of the conjugate DNAzyme against BCR-ABL tyrosine kinase was evaluated to be more significant than the native DNAzyme.

Amino Acid Sequence↗
PubMed2003

Evaluating the immune responses stimulated by CpG oligodeoxynucleotides.

CpG oligonucleotides have recently been highlighted as an immunomodulator that biases toward a Th1-dominant phenotype. To substantiate the synergism between CpG-ODNs and Ag, we introduced a linked conjugate between CpG-ODNs and Ag and the antiviral effect of antigen-conjugated CpG-ODNs therapy following an infection of mice with the influenza virus A. We found that the conjugate inhibited the influenza virus infection more efficiently than the coadministration of the unconjugated CpG-ODNs and the Ag mixture. CpG-ODNs is effective in immunity induction and will be useful in treating virus infections.

Adjuvants, Immunologic↗
PubMed2003

Large stacking stability of a base pair-mimic nucleotide on the DNA duplex.

We synthesized novel adenosine derivatives tethering an aromatic hydrocarbon group by an amido linker. The single adenosine derivatives at 5' dangling end stabilized the DNA duplex of 5'-ATGCGCAT-3' more or equally than Watson-Crick base pair. When the number of the dangling residues increased from one to three, the duplex stability became larger by 1.8-3.6 kcal/mol. When the adenosine derivative was opposite to an abasic site in a DNA duplex, the destabilization by the abasic site was significantly reduced. These observations suggest that the adenosine derivatives developed in this study can stack with a DNA base pair by forming a base pair-mimic geometry.

Base Pairing↗
PubMed2002

Rapid enzymatic transglycosylation and oligosaccharide synthesis in a microchip reactor.

Glycosidase-promoted hydrolysis was performed in a microreaction channel. The result was compared with the reaction in a micro-test tube. Transgalactosylation on p-nitrophenyl-2-acetamide-2-deoxy-beta-D-glucopyranoside was also examined in a microreaction channel, because transglycosylation is a useful method for oligosaccharide synthesis. We examined both the forward reaction, i.e., hydrolysis, and the reverse reaction, i.e., transglycosylation, in the microreaction channel. The results showed that both hydrolysis and transglycosylation were enhanced in the microreaction channel compared with the batch reaction.

Acetylglucosamine↗
PubMedDate not supplied

DNA conjugates as novel functional oligonucleotides.

Oligodeoxynucleotides with RNA cleavage activity 1) were conjugated with amines and peptides by solid phase fragment condensation (SPFC). It was found that 29 mer DNA enzyme conjugated with spermine at its 5'-end showed higher affinity to the target RNA sequence and 40 times higher activity of cleavage than native DNA enzyme. It is also to be noted that conjugate DNA enzymes showed increased resistance against nuclease digestion.

Base Sequence↗
PubMedDate not supplied

Synthesis of DNA conjugates by solid phase fragment condensation.

Development of a novel method for the synthesis of DNA conjugates is described. Oligonucleotides were successfully conjugated with a variety of functional molecules on a solid phase (Solid Phase Fragment Condensation) using an amino, a hydroxyl, a thiol, and a carboxyl group. DNA-peptide conjugate was obtained as a pure from by a single RPHPLC purification approximately in 20% yield. Moreover, it was demonstrated that the present method was effective for the preparation of conjugate molecules, DNA-sugar, DNA-polyamine, DNA-lipid and so on. The study to create new intelligent DNAs by accumulation various biofunctions on the molecule by SPFC is now in progress in our laboratory.

Base Sequence↗