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2000 Fiscal Year Final Research Report Summary

INVESTIGATION ON THE SQUALENE CYCLASE ON THE BASES OF ORGANIC CHEMISTRY AND MOLECULAR BIOLOGY

Research Project

Project/Area Number 11660104
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Bioproduction chemistry/Bioorganic chemistry
Research InstitutionNIIGATA UNIVERSITY

Principal Investigator

HOSHINO Tsutomu  DEPARTMENT OF APPLIED BIOLOGICAL CHEMISTRY, FACULTY OF AGRICULTURE, NIIGATA UNIVERSITY, PROFESSOR, 農学部, 教授 (30165542)

Project Period (FY) 1999 – 2000
Keywordssqualene / oxidosqualene / triterpene / hopene / lanosterol / triterpene / cyclase / site-directed mutagenesis
Research Abstract

This investigation was carried out to gain insight into the squalene cyclization mechanism by using the substrate analogs and by site-directed mutagenesis experiments. We established the initiation site of the cyclization and the stabilization sites as follows. The amino acid alignment of DXDDTA motif, the acidity being enhanced by His 451, is responsible for the initiation and Phe365, Phe601 and Phe605 residues stabilize the cationic intermediates. Incubation experiments of 10-desmethylsqualene analog showed the methyl group at 10-position is most critical to the completion of squalene cyclization.

  • Research Products

    (14 results)

All Other

All Publications (14 results)

  • [Publications] T.Hoshino: "Functional analysis of Phe605, a conserved aromatic amino acid in squalene-hopene cyclases"J.Chem.Soc.Chem.Commun. 1485-1487 (2000)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Hoshino: "Unnatural natural triterpenes produced by altering into alanine at position 261 in hopene synthase and the importance of having the appropriate bulk size at this position for directing the stereochemical destiny during the polycyclization cascade"J.Chem.Soc.Chem.Commun. 441-442 (2000)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Sato: "Functional analysis of the DXDDTA motif in squalene-hopene cyclase by site-directed mutagenesis experiments : initiation site of the polycyclization reaction and stabilization site of the carbocation intermediate of the initially cyclized A-ring."Biosci.Biotechnol.Biochem.. 63. 2189-2198 (1999)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Hoshino: "New cyclization mechanism for squalene : a ring-expansion step for the five-membered C-ring intermediate in hopene biosynthesis"Biosci.Biotechnol.Biochem.. 63. 2038-2041 (1999)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Sato: "Functional analysis of phenylalanine 365 in hopene synthase, a conserved amino acid in the families of squalene and oxidosqualene cyclases"J.Chem.Soc.Chem.Commun. 2205-2206 (1999)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Hoshino: "The cyclization mechanism of squalene in hopene biosynthesis : the terminal methyl groups are critical to the correct folding of this substrate both for the formation of the five-membered E-ring and for the initiation of the polycyclization reaction"J.Chem.Soc.Chem.Commun.. 731-732 (1999)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 星野力: "スクアレン環化酵素:解明されつつある活性部位・触媒機構"バイオサイエンスとインダストリー. 59・3(印刷中). (2001)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] T.Hoshino, M.Kouda, T.Abe and T.Sato.: "Functional analysis of Phe605, a conserved aromatic amino acid in squalene-hopene cyclases"J.Chem.Soc.Chem.Commun.. 1485-1486 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] T.Hoshino, T.Abe and M.Kouda.: "Unnatural natural triterpenes produced by altering into alanine at position 261 in hopene synthase and the importance of having the appropriate bulk size at this position for directing the stereochemical destiny during the polycyclization cascade"J.Chem.Soc.Chem.Commun.. 441-442 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] T.Sato and T.Hoshino.: "Functional analysis of the DXDDTA motif in squalene-hopene cyclase by site-directed mutagenesis experiments : initiation site of the polycyclization reaction and stabilization site of the carbocation intermediate of the initially cyclized A-ring."Biosci.Biotechnol.Biochem.. 63. 2189-2198 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] T.Hoshino, M.Kouda, T.Abe and S.Ohashi.: "New cyclization mechanism for squalene : a ring-expansion step for the five-membered C-ring intermediate in hopene biosynthesis"Biosci.Biotechnol.Biochem.. 63. 2038-2041 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] T.Hoshino and T.Sato.: "Functional analysis of phenylalanine 365 in hopene synthase, a conserved amino acid in the families of squalene and oxidosqualene cyclases"J.Chem.Soc.Chem.Commun.. 2205-2206 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] T.Sato and Hoshino.: "Kinetic studies on the function of all the conserved tryptophans involved inside and outside the QW motifs of squalene-hopene cyclase : stabilizing effect of the protein structure against thermal denaturation"Biosci.Biotechnol.Biochem.. 63. 1171-1180 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] T.Hoshino and K.Kondo.: "The cyclization mechanism of squalene in hopene biosynthesis : the terminal methyl groups are critical to the correct folding of this substrate both for the formation of the five-membered E-ring and for the initiation of the polycyclization reaction"J.Chem.Soc.Chem.Commun.. 731-732 (1999)

    • Description
      「研究成果報告書概要(欧文)」より

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Published: 2002-03-26  

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