1996 Fiscal Year Final Research Report Summary
Mechanism of H^+ transport by H^+ATPase
| Project/Area Number |
07458159
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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 |
Functional biochemistry
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| Research Institution | Osaka University |
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Principal Investigator |
FUTAI Masamitsu Osaka University, ISIR,Professor, 産業科学研究所, 教授 (50012646)
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| Co-Investigator(Kenkyū-buntansha) |
OKA Toshihiko Osaka University, ISIR,Research associate, 産業科学研究所, 助手 (40263321)
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| Project Period (FY) |
1995 – 1996
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| Keywords | H^+ ATPase / ATP synthase / bafilomycin / vacuolar ATPase / lipophilic cation / Fo / F_1 / ATP |
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| Research Abstract |
H^+-ATPase transport protons coupling with the energy of ATP hydrosis, and ATP synthase synthesizes ATP coupling with proton movement. They are the two of the most the important basic enzymes in organisms. In this project, we have focused on FoF_1 type ATPase and vacuolar type ATPases.
From the extensive mutagenesis studies, we could show Lys-155, Thr-156, Glu-181 and Arg-182 of the beta subunit are forming catalytic site. We also could show that Glu-185 of the subunit is essential for the catalytic cooperativity of the enzyme. The carboxyl and amino terminal helices of the gamma subunit were shown to be essential for energy coupling between catalysis and proton transport.
The H^+ pathway of Fo is formed from the a, b, and c subunits we could show that the a subunit has six transmembrane domains and the entire Fo has a ring like structure. We have studied effects of a series of lipophilic cations on FoF_1-ATPase and vacuolar type ATPase and chloropromazine, quinacrine could in habit both enzymes. We also showed inhibitory effects of concanamycin on vacuolar type ATPase.
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