| Project/Area Number |
17591921
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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 |
Morphological basic dentistry
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| Research Institution | Nagasaki University (2006)
Iwate Medical University (2005) |
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Principal Investigator |
NEMOTO Yuko Nagasaki University, Graduate School of Biomedical Sciences, Associate Professor, 大学院医歯薬学総合研究科, 助教授 (10164667)
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| Co-Investigator(Kenkyū-buntansha) |
ONO Toshio Graduate School of Biomedical Sciences, Graduate School of Biomedical Sciences, Assistant Professor, 大学院医歯薬学総合研究科, 助手 (80050607)
KIMURA Shigenobu Iwate Medical University, School of Dentistry, Professor, 歯学部, 教授 (10177917)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2006: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2005: ¥2,300,000 (Direct Cost: ¥2,300,000)
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| Keywords | protease / protease inhibitor / oral bacteria / 自然免疫系 / MPI / 抗菌活性 |
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| Research Abstract |
The onset of periodontal disease is mostly observed at the age from 50s to 60s. Its etiological agents are some selected microorganisms, so-called periodontopathic microorganisms, but we observed that Porphyromonas gingivalis and other periodontopathic bacteria habit on the oral cavity of periodontally healthy children and young adults at the age of 20s. Therefore, these observations suggest that host factors such as antibacterial agents in the oral cavity play an important role in the onset of the diseases, and that a balance between these factors and bacterial pathogenic factors like proteases and lipopolysaccharide that cause tissue damages and inflammatory responses seems important. In this study, we investigated the processing of proteases produced by oral bacteria. In addition, mucous protease inhibitor (MPI) was focused as a host factor and its effects on oral bacterial proteases were studied.
1. Recombinant expression of MPI : His-tagged MPI expression vectors was constructed and recombinant MPI was expressed in Escherichia coli. In order to purify, inclusion body containing rMPI was prepared from bacterial lysate, dissolved, and then rMPI was purified by using affinity chromatography.
2. Effects of MPI on bacterial proteases : Inhibition activity of MPI was studied with glutamic acid specific protease (GluSE) from oral Staphylococcus epidermidis and with V8 protease and trypsin. It was demonstrated that MPI did not significantly inhibit these proteases in vitro. Processing process of GluSE was investigated by 2D-PAGE, MS, and amino acid sequencing, and as a result, signal and prepeptide sequences were identified. Prepeptide significantly inhibited the proteolytic activity of GluSE. Sequence similarity between the prepeptide and MPI was investigated.
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