2006 Fiscal Year Final Research Report Summary
Mechanism of the staphylococcal pore-forming cytolytic toxins
| Project/Area Number |
17380050
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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 | Environmental and Disaster prevention Research Institute, Tohoku Gakuin University (2006)
Tohoku University (2005) |
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Principal Investigator |
KAMIO Yoshiyuki Tohoku Gakuinn University, Institute of Enviropmental Protection, Visiting Professor, 環境防災工学研究所, 客員教授 (00109175)
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| Co-Investigator(Kenkyū-buntansha) |
KANEKO Jun Tohoku University, Department of Applied Microbiology, Research Associate, 大学院農学研究科, 助手 (30221188)
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| Project Period (FY) |
2005 – 2006
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| Keywords | staphylococcal toxin / two-component toxins / gamma-hemolysin / pore-forming / single molecule visualization / environment-sensitive fluoreophore / Recognition of target cells / Staphylococcus aureus |
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| Research Abstract |
Single-molecular imaging of the entrance of a protein into the hydrophobic environment of a cell membrane was investigated. The pre-stem of LukF, one of the two components of the pore-forming toxin staphylococcal gamma-hemolysin, was specifically labeled with 6-bromoacetyl-2-dimethylaminonaphthalene (Badan), an environment-sensitive fluorophore. Incubation of this derivative with erythrocyte an into the hydrohobic interior of the lipid bilayers. However, the increase in fluorescence was completely dependent on the interaction of Badan-labeled LukF with the gamma-hemolysin second component. Individual spots of Badan fluorescence on erythrocyte membrane were visualized that were associated with single pores. Analyses of the intensities of these fluorescent spots and their photobleaching independently showed that a single pore contained 3-4 LukF molecules. Thus, environment-sensitive fluorophore signals can be used to study the insertion of specific protein domains into cell membranes at the single-molecule level, and the use of this approach in the present study revealed that a single gamma-hemolysin pore opening contains at least three LukF molecules.
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