研究者業績

高橋 孝志

タカハシ タカシ  (Takashi Takahashi)

基本情報

所属
学習院大学 理学部 化学科
学位
Ph.D.(コロンビア大学)

J-GLOBAL ID
200901066027301826
researchmap会員ID
1000279064

外部リンク

MISC

 364
  • Takayuki Serizawa, Shigeru Miyamoto, Shinichiro Fuse, Takayuki Doi, Takashi Takahashi
    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 83(8) 942-949 2010年8月  
    Construction of the ABC ring system of taxanes via one-pot three-component coupling and intramolecular alkylation is accomplished. The 1,4-addition of a protected cyanohydrin ether to 2-methyl-2-cyclohexenone and subsequent addition of the resulting enolate to formaldehyde proceeded stereoselectively to provide the AC ring in 90% yield. The stereoselective reduction of the 2-keto group was achieved by using hydroxy-directed hydride reduction with LiAlH4. The intramolecular alkylation of the protected cyanohydrin ether furnished the ABC ring system of taxanes in 43% yield.
  • Takayuki Serizawa, Shigeru Miyamoto, Shinichiro Fuse, Takayuki Doi, Takashi Takahashi
    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 83(8) 942-949 2010年8月  
    Construction of the ABC ring system of taxanes via one-pot three-component coupling and intramolecular alkylation is accomplished. The 1,4-addition of a protected cyanohydrin ether to 2-methyl-2-cyclohexenone and subsequent addition of the resulting enolate to formaldehyde proceeded stereoselectively to provide the AC ring in 90% yield. The stereoselective reduction of the 2-keto group was achieved by using hydroxy-directed hydride reduction with LiAlH4. The intramolecular alkylation of the protected cyanohydrin ether furnished the ABC ring system of taxanes in 43% yield.
  • Emi Inoko, Yuji Nishiura, Hiroshi Tanaka, Takashi Takahashi, Koichi Furukawa, Ken Kitajima, Chihiro Sato
    GLYCOBIOLOGY 20(7) 916-928 2010年7月  
    The monoclonal antibody mAb.A2B5 is a marker for the detection of oligodendrocyte progenitor cells that differentiate into type-2 astrocytes and oligodendrocytes. It is also a useful antibody for separating these cells from other lineage populations. The epitope of this antibody is considered to be the gangliosides GT3 and GQ1c. In this study, we sought to define more precisely the structure of the epitope. Accordingly, we chemically synthesized defined oligosialic acid structures linked to phosphatidylethanolamine and bovine serum albumin and used these to determine the antigenic specificity. mAb.A2B5 recognized the Neu5Ac alpha 2 -> 8Neu5Ac alpha 2 -> 8Neu5Ac alpha -> structure on both glycolipids and glycoproteins. We then examined whether the mAb.A2B5 epitope exists on glycoproteins in developing mouse brains. Western blot analyses revealed the expression of four glycoproteins reactive with the mAb.A2B5, and their expression was dependent on the stage of neural development. All the immunoreactivity in these glycoproteins with mAb.A2B5 disappeared after sialidase treatment and were resistant to chloroform/methanol extraction. These epitopes were also detected in brain homogenates from both GD3 synthetase-null and GD3/GD2 synthetase double null mice. These findings show that the alpha 2,8-trisialic acid (triSia) unit recognized by mAb.A2B5 resides not only on gangliosides but also on glycoproteins in developing mouse brain. We postulate that the triSia structure on glycoproteins may be involved in oligodendrocyte differentiation, similar to the case with the alpha 2,8-triSia structure on gangliosides. Real time polymerase chain reaction analysis of the developmental expression of all known ST8Sia genes, which are responsible for the biosynthesis of alpha 2,8-linked Sia residues, showed that ST8Sia III gene expression correlated with expression of the triSia epitope. We suggest that ST8Sia III is the principal sialyltransferase responsible for synthesis of the alpha 2,8-triSia units on glycoproteins.
  • Emi Inoko, Yuji Nishiura, Hiroshi Tanaka, Takashi Takahashi, Koichi Furukawa, Ken Kitajima, Chihiro Sato
    GLYCOBIOLOGY 20(7) 916-928 2010年7月  
    The monoclonal antibody mAb.A2B5 is a marker for the detection of oligodendrocyte progenitor cells that differentiate into type-2 astrocytes and oligodendrocytes. It is also a useful antibody for separating these cells from other lineage populations. The epitope of this antibody is considered to be the gangliosides GT3 and GQ1c. In this study, we sought to define more precisely the structure of the epitope. Accordingly, we chemically synthesized defined oligosialic acid structures linked to phosphatidylethanolamine and bovine serum albumin and used these to determine the antigenic specificity. mAb.A2B5 recognized the Neu5Ac alpha 2 -> 8Neu5Ac alpha 2 -> 8Neu5Ac alpha -> structure on both glycolipids and glycoproteins. We then examined whether the mAb.A2B5 epitope exists on glycoproteins in developing mouse brains. Western blot analyses revealed the expression of four glycoproteins reactive with the mAb.A2B5, and their expression was dependent on the stage of neural development. All the immunoreactivity in these glycoproteins with mAb.A2B5 disappeared after sialidase treatment and were resistant to chloroform/methanol extraction. These epitopes were also detected in brain homogenates from both GD3 synthetase-null and GD3/GD2 synthetase double null mice. These findings show that the alpha 2,8-trisialic acid (triSia) unit recognized by mAb.A2B5 resides not only on gangliosides but also on glycoproteins in developing mouse brain. We postulate that the triSia structure on glycoproteins may be involved in oligodendrocyte differentiation, similar to the case with the alpha 2,8-triSia structure on gangliosides. Real time polymerase chain reaction analysis of the developmental expression of all known ST8Sia genes, which are responsible for the biosynthesis of alpha 2,8-linked Sia residues, showed that ST8Sia III gene expression correlated with expression of the triSia epitope. We suggest that ST8Sia III is the principal sialyltransferase responsible for synthesis of the alpha 2,8-triSia units on glycoproteins.
  • Jun Takahashi, Ichiro Hijikuro, Takeshi Kihara, Modachur G. Murugesh, Shinichiro Fuse, Yoshinori Tsumura, Akinori Akaike, Tetsuhiro Niidome, Takashi Takahashi, Hachiro Sugimoto
    Bioorganic and Medicinal Chemistry Letters 20(5) 1718-1720 2010年3月  

講演・口頭発表等

 100