| Project/Area Number |
10670270
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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 |
Bacteriology (including Mycology)
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| Research Institution | Kitasato university |
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Principal Investigator |
SEKIYA Kachiko Kitasato Univ., Pharm. Science, Assis. Prof., 薬学部, 講師 (30050579)
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| Co-Investigator(Kenkyū-buntansha) |
FUTAESAKU Yutaka Kitasato Univ., Allied Health Sciences, Prof., 医療衛生学部, 教授 (50014197)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 1999: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1998: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | pore-forming toxins / cell membrane damage / electron spectroscopic imaging / ultrastructure / negative-staining / liposome / haemolysis / streptolysin O / 細胞溶解毒素 / 孔形成毒素 / チオール活性化毒素 |
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| Research Abstract |
The damage to cell membranes by bacterial fore-forming-toxins such as streptolysin O (SLO) and botulinolysin (BLY) was studied ultrastructurally by electron spectroscopic imaging (ESI). The newly developed technique of ESI provides the fine molecular images with a low noise-to-signal ratio even if it is on a supporting film. An imaging plate (IP) combined with ESI decreases the electron beam exposure on the biological specimens to one hundredth since they are very susceptible. The ring formed by SLO is a double and coaxial ring-shaped structure. The SLO molecules of two types which construct one ring are identical by the different iso-electric point (pI). While the BLY ring formed on erythrocyte membranes is observed as a similar structure of SLO ring, it is obviously constructed by BLY molecules of a single type evaluated by immuno-electrophoresis. The application of ESI offers additionally the successful data from the extensive biological specimens such as human hair, ferritin particles and hydroxyapatite crystals. To observe a carbon image of biological specimens, we developed a non-carbon supporting film made by silicon dioxide. The film offers successively an carbon image of ultra-cryosection of E. coli. It is expected to use the non-carbon film to the study of the pore-forming toxins in the future since the film is strong enough to support a whole bacterium, E. coli, the granularity of surface of the film is fine. A method of membrane-cramp by freeze-fracture is also ideal to evaluate the role of cholesterol in membrane damage with the pore-forming toxins. As combining above three methods, the study to clarify the mechanism of pore-formation with cytolitic toxins has been progressing.
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