Masami Mizu
University of Kitakyushu
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Featured researches published by Masami Mizu.
Organic and Biomolecular Chemistry | 2004
Teruaki Hasegawa; Tomohisa Fujisawa; Munenori Numata; Takahiro Matsumoto; Mariko Umeda; Ryouji Karinaga; Masami Mizu; Kazuya Koumoto; Taro Kimura; Shiro Okumura; Kazuo Sakurai; Seiji Shinkai
Schizophyllans carrying beta-lactoside and alpha-mannoside appendages were prepared from native schizophyllan through NaIO4 oxidation followed by reductive amination using aminoethyl-beta-lactoside and alpha-mannoside, respectively. The resulting schizophyllans form stable macromolecular complexes with polynucleotides, such as poly(C) and poly(dA). Specific affinity between these macromolecular complexes and saccharide-binding proteins was demonstrated by surface plasmon resonance and agarose gel staining assays. beta-lactoside-appended schizophyllan enhanced an antisense activity in hepatocytes which express lactoside-binding proteins on their cell surfaces.
Chemical Communications | 2004
Teruaki Hasegawa; Mariko Umeda; Takahiro Matsumoto; Munenori Numata; Masami Mizu; Kazuya Koumoto; Kazuo Sakurai; Seiji Shinkai
A schizophyllan (beta-1,3-glucan) derivative carrying lactose-appendages prepared by reductive amination can form stable macromolecular complexes with polynucleotides, shows excellent affinity with a lactose-binding lectin, and effectively mediates gene transfection into hepatocytes.
Bioorganic Chemistry | 2003
Kazuo Sakurai; Ristuko Iguchi; Masami Mizu; Kazuya Koumoto; Seiji Shinkai
Schizophyllan belongs to a beta-1,3-D-glucan family, which exists as a random coil in dimethyl sulfoxide (DMSO) and as a triple helix in water, respectively. The schizophyllan single chain forms a complex with single-stranded homo RNAs in water/DMSO mixed solvents. Using circular dichroism, we studied the complexation and its stability as a function of apparent pH (pH(*)) in a mixed solvent system and as a function of the salt concentration. The complex is formed in the pH(*) range 6.5-10, and dissociated in the pH(*) range 4-6. Both poly(A) and poly(C) adopt a double strand in the pH(*) range 4-6 and a single strand in the pH(*) range 6.5-10. Therefore, the conformational change of each polynucleotide is responsible for dissociation/association of the complex, i.e., the single strand of the polynucleotides can form complexes, whereas the double one cannot. This result indicates that hydrogen bonding and similarity of the helix parameters are essential for the complex formation. The melting temperature of the complex reaches the maximum around 0.05 M of NaCl and KCl, and the value of the maximum temperature depends on the cation species.
Chemical Communications | 2001
Masami Mizu; Taro Kimura; Kazuya Koumoto; Kazuo Sakurai; Seiji Shinkai
A single chain of schizophyllan, one of the β-1,3-glucan family, can form a stoichiometric complex with poly(dA) and the poly(dA)’s conformation and the complex stability strongly depends on the base length.
Journal of The Chemical Society-perkin Transactions 1 | 2002
Kazuya Koumoto; Taro Kimura; Masami Mizu; Toyoki Kunitake; Kazuo Sakurai; Seiji Shinkai
Recently, we found that schizophyllan (SPG), which is a natural and neutral polysaccharide, can form macromolecular complexes with certain polynucleotides. In order to increase the stability and the affinity of the complexes, we synthesized a 2-aminoethanol-appended SPG (N-s-SPG) by utilizing periodate oxidation and reductive amination. Although the modification level was only 2.4 ± 0.3%, the melting temperature of the poly(C)–N-s-SPG complex was increased by 8 °C comparing with the poly(C)–s-SPG complex. In addition, the conformation of the complex was scarcely perturbed by the introduction of amino groups. When we formed complexes of N-s-SPG and other polynucleotides, the melting temperature of their complexes increased without exception. Moreover, the amino modification induced complexation with poly(U), which does not form a complex with SPG. The affinity for the short chain nucleotide was also enhanced. These results indicate that the present modification method is quite useful to improve complex stability and we believe, therefore, that this strategy will make it possible to apply SPG to a novel gene carrier.
Biomacromolecules | 2001
Kazuo Sakurai; Masami Mizu; Seiji Shinkai
Biochimica et Biophysica Acta | 2004
Takahiro Matsumoto; Munenori Numata; Takahisa Anada; Masami Mizu; Kazuya Koumoto; Kazuo Sakurai; Takeshi Nagasaki; Seiji Shinkai
Bioconjugate Chemistry | 2004
Takeshi Nagasaki; Masaya Hojo; Atsushi Uno; Taku Satoh; Kazuya Koumoto; Masami Mizu; Kazuo Sakurai; Seiji Shinkai
Journal of the American Chemical Society | 2004
Masami Mizu; Kazuya Koumoto; Takahisa Anada; Takahiro Matsumoto; Munenori Numata; Seiji Shinkai; Takeshi Nagasaki; Kazuo Sakurai
Biomaterials | 2006
Ryouji Karinaga; Takahisa Anada; Jusaku Minari; Masami Mizu; Kazuya Koumoto; Junji Fukuda; Kohji Nakazawa; Teruaki Hasegawa; Munenori Numata; Seiji Shinkai; Kazuo Sakurai