1995 Fiscal Year Final Research Report Summary
Bio-organic Chemistry on Egg Diapause of Silkworm
| Project/Area Number |
05453164
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Bioproduction chemistry/Bioorganic chemistry
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| Research Institution | Mie University |
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Principal Investigator |
IMAI Kunio Mie Univ.Fac.Bioresources Associate Professor, 生物資源学部, 助教授 (80109313)
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| Co-Investigator(Kenkyū-buntansha) |
YAMASHITA Okitsugu Nagoya Univ.Fac.Agriculture Professor, 農学部, 教授 (50023411)
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| Project Period (FY) |
1994 – 1995
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| Keywords | Diapause hormone / Silkworm / Diapause hormone derivatives / Egg diapause / Lipophilic peptides / SGNP / Chemical synthesis |
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| Research Abstract |
SEARCH FOR NATURAL SGNPS AND NEW DIAPAUSE INDUCING SUBSTANCES
Natural alpha-, beta- and gamma-SGNP were searched for in the extract of the suboesophageal ganglions of silkworm. alpha- and gamma-SGNP were isolated and identified, and beta-SGNP was speculated to exist.
To investigate the new diapause inducing substances, the heads of male silk moths were collected. They were extrated with water and several organic solvents. Most of the extracts showed the diapause inducing activity, and the result suggested that the organ contains many kinds of active substances. They were purified by repeated chromatography and one of the active substances (VAP peptide) was isolated. It had unique structure, physicochemical feature and biological activity.
PEPTIDE SYNTHESIS AND BIOLOGICAL ACTIVITY OF SYNTHETIC PEPTIDES
Diapause hormone (DH) , SGNPs and a fragment analog of VAP peptide were chemically synthesized and the synthetic peptides were used for preparation of antibodies and for the preparation of derivatives.
A procedure to derivatize the N terminus of DH was developed, as the biological activity was reduced when free DH molecule was simply treated with the derivatizing reagents. Acylated derivatives, fluorescent and pigmented derivative and photoaffinity labeled derivative were successfully prepared.
The C terminal pentapeptides and their analogs were synthesized and their biological activities were compared to each other. The result suggested 1) amide structure at C terminus is important, 2) the tripeptide amide is the smallest unit for biological function, 3)modification of the unit enhances the biological acitivity.
The results of the present research indicated the possiblility to clarify the mechanism for diapause induction and to design and to create the artificial diapause inducing substances.
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