Project/Area Number |
21370070
|
Research Category |
Grant-in-Aid for Scientific Research (B)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Biophysics
|
Research Institution | Nagoya University |
Principal Investigator |
|
Co-Investigator(Kenkyū-buntansha) |
MURAKAMI Midori 名古屋大学, 理学研究科, 助教 (20324387)
IHARA Kunio 名古屋大学, 遺伝子実験施設, 准教授 (90223297)
IWASA Tatsuo 室蘭工業大学, 工学部, 教授 (00133926)
|
Project Period (FY) |
2009 – 2011
|
Project Status |
Completed (Fiscal Year 2011)
|
Budget Amount *help |
¥19,110,000 (Direct Cost: ¥14,700,000、Indirect Cost: ¥4,410,000)
Fiscal Year 2011: ¥5,330,000 (Direct Cost: ¥4,100,000、Indirect Cost: ¥1,230,000)
Fiscal Year 2010: ¥5,330,000 (Direct Cost: ¥4,100,000、Indirect Cost: ¥1,230,000)
Fiscal Year 2009: ¥8,450,000 (Direct Cost: ¥6,500,000、Indirect Cost: ¥1,950,000)
|
Keywords | 結晶構造解析 / ロドプシン / プロトンポンプ / ハロロドプシン / 視物質 / 古細菌 / レチナール蛋白質 / X線結晶構造解析 / 光駆動プロトンポン / 塩素イオンポンプ / 膜タンパク質 / イカ・ロドプシン / バクテリオロドプシン / アーキロドプシン / イカロドプシン / イオンポンプ / Gタンパク質共役レセプター / レチナールタンパク質 |
Research Abstract |
(1) Crystallization of retinal proteins by the membrane fusion method: (1) The chloride ion pump from Natoronomonas pharaonis, pharaonis halorhodopsin(pHR), was crystallized, and its structure was determined at 2. 0 Aresolution. (2) Deltarhodopsin(dR3), a light-driven proton pomp found in the cell membrane of Haloterrigena thermotolerans, was crystallized, and its structure was determined at 2. 7 A resolution. (2) Structural analyses of the photoreaction intermediates of bacteriorhodopsin: (1) The structure of the M intermediate was determined at various pH levels. It was shown that the formation of M intermediate at neutral pH is accompanied by a complete destruction of the paired structure of two glutamates in the proton release channel, while this destruction is incomplete at a weakly acidic pH. (2) Using the Leu93-to-Ala mutant(BR_L93A) of bacteriorhodopsin, the structure of the O intermediate was determined at 2. 3 A resolution (3) Structural analyses of the light-driven chloride ion pu
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mp(pHR): (1) The crystal structures of the O-like blue form and the yellow anion-depleted form of pHR were determined at 1. 8 ? 2. 0 A resolutions. The result allowed us to elucidate the mechanism by which the chloride ion is removed from the active site near the protonated Schiff base of retinal. (2) The crystal structure of an M-like intermediate of the pHR-azide complex was determined at 2. 3 A resolution. It is shown that the cytoplasmic half of helix F undergoes a large structural change during the proton pumping cycle (3) A mutant of pHR(pHR_ΔBC) in which a long loop between transmembrane helices B and C was partially deleted was expressed in E. coli. It was shown that the photocycle of pHR_ΔBC is not influenced by the membrane potential, while the uptake process of chloride ion is much faster than observed in the wild-type pHR. (4) Structural analyses of squid rhodopsin (1) The primary photochemical reaction intermediate(Baso) of squid rhodopsin was determined at 2. 7 A resolution. (2) Light-induced structural changes in octopus rhodopsin(oRh) were investigated by small-angle X-ray scattering method. Less
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