1993 Fiscal Year Final Research Report Summary
Research on the anti-oxidative stress system in insects
| Project/Area Number |
04660043
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
植物保護
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| Research Institution | The University of Tokyo |
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Principal Investigator |
ISHIKAWA Yukio The University of Tokyo, Department of Agriculture Associate Professor, 農学部, 助教授 (60125987)
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| Project Period (FY) |
1992 – 1993
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| Keywords | Delia antiqua / Superoxide dismutase / Purification / Monoclonal antibody / Oxidative stress |
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| Research Abstract |
The changes of superoxide dismutase (SOD) activity in the onion maggot, Delia antiqua, were investigated in relation to the growth of larvae and its responsiveness to oxidative stress. Specific SOD activity was very high in the newly hatched larvae, but it decreased rapidly when they started feeding a synthetic diet, which is free from plant secondary compounds. By contrast, SOD activity was increased in a few hours after feeding onion pieces or its homogenate. As ethanol extract of onion had no apparent effect on SOD activity, SOD-inducing compound (s) in onion was considered to be produced by tissue injuries, including those caused by insect feeding.
SOD of D.antiqua was purified to apparent homogeneity by ammonium sulfate fractionation, followed by anion exchange, hydrophobic interaction and gel filtration chromatographies. Native molecular weight was estimated as 32,000. SDS-PAGE revealed only one subunit of 16,000, indicating SOD is a homodimer. Isoelectric focusing revealed 3 charge isomers of pIs 5.3,5.5 and 5.7. Specific activity of purified SOD was 4250 units/mg protein. A monoclonal antibody (MAb, aSOD2B7) raised against Delia SOD recognized only SOD of the same genus, but another MAb (aSOD1H11) recognized SOD of Drosophila melanogaster as well.
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