Insect Diapause, its Chemical Control and Elucidation of Molecular Mechanism

• Project/Area Number: 04453138
• Research Category: Grant-in-Aid for General Scientific Research (B)
• Allocation Type: Single-year Grants
• Research Field: 製造化学・食品
• Research Institution: Nagoya University
• Principal Investigator: ISOBE Minoru Nagoya University, School of Agriculture, Professor, 農学部, 教授 (00023466)
• Co-Investigator(Kenkyū-buntansha): YAMASHITA Okitugu Nagoya University, School of Agriculture, Professor, 農学部, 教授 (50023411) ; OHTANI Ikuko Nagoya University, School of Agriculture, Assistant Professor, 農学部, 助手 (40247680) ; ICHIKAWA Yoshiyasu Nagoya University, School of Agriculture, Associate Professor, 農学部, 助教授 (60193439) ; 西川 俊夫 名古屋大学, 農学部, 助手 (90208158)
• Project Period (FY): 1992 – 1993
• Project Status: Completed (Fiscal Year 1993)
• Budget Amount: ¥6,600,000 (Direct Cost: ¥6,600,000); Fiscal Year 1993: ¥1,300,000 (Direct Cost: ¥1,300,000); Fiscal Year 1992: ¥5,300,000 (Direct Cost: ¥5,300,000)
• Keywords: diapause hormone / peptide / amidated C-termunal peptide / hydrophobicity / HPLC / silkworm, Bombyx mori / structure relationship

Research Abstract

To determine the structure-activity relationships of diapause hormone of the silkworm, Bombyx mori, a series of peptide analogs having different chain length starting from the parent C-termunus an analogs having free acid C-terminal were chemically synthesized by solid-phase Fmoc methodology and were further purified by HPLC.Bioassay elicited the non-active nature of the free acid C-termunus and the retained activity of those shorter chain with the amidated C-termunal analogs among which the response depended on the length of the chain. It means that the active peptides required two minimal elements, namely the sequence near and the amidation of the C-termunus. The amidated C-termunus did not show better protective role against enzymatic digestion in pupal and larval haemolymph than the free acid C-termunal analog. This suggested its involvement in the existence of a certain higher order structure needed in expression of biological activity. Moreover, as most of the hydrophobic amino acids locate close to the C-termunal portion, the sequence near that terminus could be alternatively related to the necessary hydrophobicity. Consequently, both the hydrophobicity of the portion near and the amidation of the C-termunus were indispensable structure for diapause hormone activity.

Research Products

• [Publications] Sato,Y.: "Precursor Polyprotein for multiple neuropeptides secreted from the suboesophageal ganglion of the silkworm Bombyx mori::Characterization of the cDNA encoding the diapause hormone precursor and identification of additional peptides." Proc.Natl.Acad.Sci.USA(neurobiology). 90. 3251-3255 (1993)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Isobe,M.: "Silkworm Diapause Hormone,Structure-Activity Relationships-----Indispensable Role of C-Terminal Amide." J.Insect Biochemistry and Molecular Biology.(in Press).
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Sato, Y.: "Precursor Polyprotein for multiple neuropeptides secreted from the suboesophageal ganglion of the silkworm Bombyx mori : Characterization of the cDNA encoding the diapause hormone precursor and identification of additional peptides." Proc.Natl.Acad.Sci.USA (neurobiology). 90. 3251-3255 (1993)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Isobe, M.: "Silkworm Diapause Hormone, Structure-Activity Relationships--Indispensable Role of C-Terminal Amide." J.Insect Biochemistry and Molecular Biology. (in Press).
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Sato,Y.: "Precursor Polyprotein for multiple neuropeptides secreted from the suboesophageal ganglion of the silkworm Bombyx mori::Characterization of the cDNA encoding the diapause hormone precursor and identification of additional peptides." Proc.Natl.Acad.Sci.USA(neurobiology). 90. 3251-3255 (1993)
• [Publications] Isobe,M.: "Silkworm Diapause Hormone,Structure-Activity Relationships-----Indispensable Role of C-Terminal Amide." J.Insect Biochemistry and Molecular Biology.(in press).
• [Publications] Yukihiro Sato: "A New Diapause Hormone Molecule of the Silkworm,Bombyx mori" Proceedings of the Japan Academy. 68. 75-79 (1992)