| Project/Area Number |
13142201
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| Research Category |
Grant-in-Aid for Scientific Research on Priority Areas
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| Allocation Type | Single-year Grants |
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| Review Section |
Biological Sciences
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
KAYA Shunji Hokkaido Univ., Faculty of Sci., Associate Prof., 大学院理学研究科, 助教授 (90186023)
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| Co-Investigator(Kenkyū-buntansha) |
SUZUKI Hiroshi Asahikawa Medical College, Prof, 医学部, 教授 (50183421)
HAYSHI Yutaro Kyorin Univ., School of Medicine, Prof., 医学部, 教授 (10086556)
TANIGUCHI Kazuya Hokkaido Univ., Faculty of Sci., Prof (2001-2003), 大学院理学研究科(平成13〜14年度), 教授 (40028204)
IMAGAWA Toshiaki Hokkaido Univ., Faculty of Sci., Associate Prof. (2003-2006), 大学院理学研究科(平成15〜17年度), 助教授 (20142177)
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| Project Period (FY) |
2001 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥69,900,000 (Direct Cost: ¥69,900,000)
Fiscal Year 2005: ¥10,500,000 (Direct Cost: ¥10,500,000)
Fiscal Year 2004: ¥11,800,000 (Direct Cost: ¥11,800,000)
Fiscal Year 2003: ¥13,500,000 (Direct Cost: ¥13,500,000)
Fiscal Year 2002: ¥16,400,000 (Direct Cost: ¥16,400,000)
Fiscal Year 2001: ¥17,700,000 (Direct Cost: ¥17,700,000)
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| Keywords | Sodium Pump / Fluorescent Probe / Single-molecule observation / Proton Pump |
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| Research Abstract |
(1) Protomeric images of Na/K-ATPase and H/K-ATPase were observed by electron microsoopy(EM) after rotary-shadowing the solubilized enzyme preparation. Without cross-linking the preparation, dimeric and tetrameric molecules were detected by EM, indicating that the pump molecules are assembled in oligomer
(2) We have established the method for determining the oligomericity of P-type ATPases by means of single-molecule observation of fluorescently labeled enzyme using the total internal reflection fluorescence microscopy.
(3) Tetrameric structure of P-type ATPases has been determined not only Na/K-ATPase but also H/K-ATPase. In case ofH/K-ATPase, functional unit of the enzyme was shown to be tetraprotomer based on the relationship between the enzyme activity and the oligomeric structure.
(4) Analysis of the single mutations ofATP-binding region of Na/K-ATPase suggested that the ATPase molecule has one ATP binding site, which changes the affinity for ATP depending on the ligands present and the ATPase molecules form oligomer to maintain the interaction between them. We have estimated the third Na+ binding region of Na/K-ATPase at the first time.
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