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Mizuki Takahashi

Publications and source records attributed to Mizuki Takahashi.

5 recordsLinked to original sources

Site-selective monotitanation of dialkynylpyridines and its application for preparation of highly fluorescent pi-conjugated oligomers.

Reaction of Ti(O-i-Pr)(4)/2i-PrMgCl reagent with 2,n-bis[(trimethylsilyl)ethynyl]pyridines, where n is 3, 4, 5, and 6, or with 3,4-bis[(trimethylsilyl)ethynyl]pyridines, proceeded with excellent site-selectivity to afford the corresponding monotitanated complex. Synthetic application of the reaction was demonstrated by an efficient preparation of pi-conjugated oligomers having pyridine and enyne units alternately, which possess intense blue fluorescence emission.

Journal Article↗

Peptide arrays with designed secondary structures for protein characterization using fluorescent fingerprint patterns.

To realize a practical high-throughput protein-detection system, novel peptide arrays have been constructed using designed peptide libraries with loop, alpha-helix, or beta-strand structures. Here, we describe the overview of the reported designed peptide arrays with loop and alpha-helix structures and the new results of those with beta-strand structures. Initially, several model peptides known to interact with model structured proteins were selected to establish the present strategy for high-throughput detection of proteins. The fluorescent probes and suitable scaffolds of peptides were examined for the effective detection of proteins. The detection methods were established in solution and in an immobilized manner using the model systems. In the case of alpha-helix peptide, the response of a peptide with fluorescent resonance energy transfer between two probes at both termini was several times higher than that of a peptide with a single probe. In the cases of peptides with other structures, however, proteins were effectively detectable even by the fluorescent change of one probe. Furthermore, structurally focused libraries consisting of a total of ca. 250 different peptides based on the model peptides with secondary and/or tertiary structures were constructed with systematic replacement of residues. Using these libraries, various proteins were characterized effectively to give their own fluorescent "protein fingerprint" patterns. The resulting protein fingerprints correlated with the recognition properties of the proteins. These studies demonstrate that arrays with peptide libraries based on designed structures can be promising tools for detecting the target proteins. Designed synthetic peptides play roles as the capturing agents to be developed for practical protein chips.

Amino Acid Sequence↗

Peptide arrays with designed alpha-helical structures for characterization of proteins from FRET fingerprint patterns.

A practical high-throughput protein detection system is described, based on synthetic peptide arrays consisting of designed alpha-helical peptides, detected by fluorescence resonance energy transfer (FRET). Initially a model alpha-helical peptide known to interact with a structured protein, calmodulin, was selected to establish the strategy for high-throughput detection. In comparison to peptides with a single probe, a much higher FRET response has been observed with two fluorescent probes (7-diethylaminocoumarin-3-carboxylic acid and 5(6)-carboxy-fluorescein) at both termini of the synthetic peptides. To establish a reproducible high-throughput detection system, peptides were also immobilized onto a solid surface for detection of the target proteins. A small library of 112 different peptides was constructed, based on a model of the alpha-helical peptide with systematic replacement of residues carrying specific charges and/or hydrophobicities. The library was used to effectively characterize various proteins, giving their own 'protein fingerprint' patterns. The resulting 'protein fingerprints' correlate with the recognition properties of the proteins. The present microarray with designed synthetic peptides as the capturing agents is promising for the development of protein detection chips.

Amino Acid Sequence↗

Construction of a protein-detection system using a loop peptide library with a fluorescence label.

Construction of a novel protein-detection system was carried out using a designed peptide library with fluorescent labels based on loop structures. As a basic model study, detection of alpha-amylase using fluorescent-labeled peptides derived from an active loop of tendamistat was examined. The detection methods for proteins with immobilized peptides as well as peptides in solution have been successfully established. Based on these results, a loop peptide library that has various turn sequences grafted on a stable loop structure has been constructed. Various proteins with recognition patterns corresponding, for instance, to "protein fingerprints" could be detected using an immobilized peptide library. The present results suggest that the system can be applied to the development of a peptide microarray that behaves as a protein chip.

Amino Acid Sequence↗

Construction of the novel conformationally-restricted peptide library for screening of peptides that control the interaction between nucleobases.

A unique conformationally-restricted peptide library was constructed using a loop structure as a structural scaffold. This library was used for the screening of the amino acid sequences that control the interaction between nucleobase triplets. The peptides have PNAs at the C-terminus as the recognition site and the random amino acid sequence at the N-terminus as the effector for the interaction between PNA and its complementary DNA triplets. From the peptide libraries constructed by the positional scanning method, the sequences that affect the interaction between PNA and complementary DNA were selected. The difference in the characteristic results by using A-T and G-C pairs was presented. This study would also give us some useful information about interaction between peptides and nucleic acids, such as relevances between these biomolecules in a prebiotic era.

Animals↗