| Project/Area Number |
15380054
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied microbiology
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| Research Institution | Tohoku University |
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Principal Investigator |
KAMIO Yoshiyuki Tohoku University, Graduate School of Agricultural Science, Professor, 大学院・農学研究科, 教授 (00109175)
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| Co-Investigator(Kenkyū-buntansha) |
KANEKO Jun Tohoku University, Graduate School of Agricultural Science, Assistant Professor, 大学院・農学研究科, 助手 (30221188)
HIGUCHI Hideo Tohoku University, Graduate School of Engineering, Associate Professor, 大学院・工学研究科, 助教授 (90165093)
冨田 敏夫 東北大学, 大学院・農学研究科, 助教授 (00126129)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥16,000,000 (Direct Cost: ¥16,000,000)
Fiscal Year 2004: ¥6,000,000 (Direct Cost: ¥6,000,000)
Fiscal Year 2003: ¥10,000,000 (Direct Cost: ¥10,000,000)
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| Keywords | Staphylococcus aureus / γ-hemolysin / two-component hemolytic toxin / Pore-foming mechanism / Recognition of target cells / Staphylococcus aureus / leukocidin / γ-hemolysin / 膜孔形成 / 一分子技術 |
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| Research Abstract |
Staphylococcal γ-hemolysin (Hlg), leukocidin (Luk), and Panton-Valentine leukocidin (PVL) are two-component and hetero-oligomeric pore-forming cytolytic toxins (or cytolysin), that were first identified in bacteria. No information on the existence of hetero-oligomeric pore-forming cytolytic toxins in bacteria except for staphylococcal strains is available so far. Hlg (Hlg1 of 34 kDa/Hlg2 of 32 kDa) effectively lyses erythrocytes from human and other mammalian species. Luk (LukF of 34 kDa/LukS of 33 kDa) is cytolytic toward human and rabbit polymorphonuclear leukocytes and rabbit erythrocytes, and PVL (LukF-PV of 34 kDa/LukS-PV of 33 kDa) reveals cytolytic activity with a high cell specificity to leukocytes. Hlg1 is identical to LukF and that the cell specificities of the cytolysins are determined by Hlg2 and LukS. Based on the primary and 3-dimensional structures of the toxin components, Hlg, Luk, and PVL are thought. to form a family of proteins.
Recently, the assembly mechanism of the LukF and Hlg2 monomers into pore-forming hetero-oligomers of Hlg on human erythrocyte membranes has been clarified for the first time by our study using a single-molecular fluorescence imaging technique. We estimated 11 sequential equilibrium constants for the assembly pathway which includes the beginning with membrane binding of monomers, proceeds through single pore oligomerization, and culminates in the formation of clusters of the pores.
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