| Project/Area Number |
07680673
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Functional biochemistry
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| Research Institution | University of Tsukuba |
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Principal Investigator |
BANNAI Shiro Institute of Basic Medical Sciences University of Tsukuba, Professor, 基礎医学系, 教授 (70019579)
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| Co-Investigator(Kenkyū-buntansha) |
SATO Hideyo Institute of Basic Medical Sciences University of Tsukuba, Lecturer, 基礎医学系, 講師 (60235380)
ISHII Tetsuro Institute of Basic Medical Sciences University of Tsukuba, Assistant Professor, 基礎医学系, 助教授 (20111370)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1996: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1995: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | Reactive oxygen / Antioxidant / Stress proteins / Oxidative stress / Macrophages / ストレスタンパク質 / 分子クローニング |
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| Research Abstract |
We have found that a novel protein with a molecular mass of 23 kDa, designated MSP23, is induced by oxidative stress in mouse peritoneal macrophages and cloned the cDNA for the protein. In this study, the homologous protein to MSP23 was pruified from the liver in order to investigate the function of MSP23. It was demonstrated that the purified MSP23 possessed the thiol-specific antioxidant activity and that it protected glutamine synthetase from inactivation by a mixed metal-thiol oxidation. It was also found that MSP23 bound hemin and that the thiol-specific antioxidant activity of MSP23 was lost by the binding.
MSP23 prevented the inactivation of the enzyme by oxidative stress in the presence of dithiothreitol. This implies that the thiol-compound is involved in the reduction of MSP23 which had been oxidized by the oxidative stress. We, therefore, investigated the antioxidant activity of MSP23 when thioredoxin is added to the reaction mixture in vitro to explore the redox system for MPS23. However, the thioredoxin system did not work as the reduction system for MSP23. The redox systems related to MSP23 deserves further exploration.
We have investigated the induction of MPS23 by oxidative stress in other types of cells. In cultured vascular smooth muscle cells, MSP23 was strongly induced by oxidized low density lipoprotein, suggesting that the antioxidant activity of this protein involved in the pathogenesis and progression of atherosclerosis. On the other hand, MSP23 was not induced in caerulein-induced acute pancreatitis although oxidative stress has been implicated in the pathogenesis of this disease.
We tried to obtain a large amount of MPS23 using the yeast expression system because it was difficult to have enough amount of the purified protein from the liver. The cDNA of MPS23 was subcloned into the yeast expression vector and the transformants were screened. These transformants produced MSP23 but the amount was far less than expected.
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