1988 Fiscal Year Final Research Report Summary
Structure and Function of Photosensory Pigments in Unicellular Organs.
| Project/Area Number |
61304069
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| Research Category |
Grant-in-Aid for Co-operative Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
生物物性学
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| Research Institution | Sapporo Medical College |
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Principal Investigator |
TSUDA Motoyuki Sapporo Medical College, 医学部, 助教授 (60045458)
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| Co-Investigator(Kenkyū-buntansha) |
WATANABE Masakatsu National Institute for Basic Biology, 大型スペクトル室, 助手 (40124226)
KOYAMA Yasushi Kansei Gakuin University, 理学部, 教授 (90079666)
SHICHIDA Yoshinori Kyoto University, 理学部, 助手 (60127090)
KOUYAMA Tsutomu The Institute of Physical and Chemical Research, 生物物理研究室, 研究員 (30170210)
KOBAYASHI Takayoshi University of Tokyo, 理学部, 助教授 (60087509)
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| Project Period (FY) |
1986 – 1988
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| Keywords | Sensory Rhodopsin / Phoborhodopsin / Photoreceptor / Halobacteria / 走光性 |
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| Research Abstract |
Rhodopsin, visual pigment in animal retina, is composed of retinal and seven helices protein. This retinal protein was also found in archibacteria, halobacterium halobium. Bacteriorhodopsin and halorhodopsin were light driven ion pumps. Third pigment, which was found by Tsuda's group and Spudich's group, was characterized as a photoreceptor for phototaxis. In addition to sR, phoborhodopsin (pR) was found as a fourth pigment in holobacteria, which is a receptor for photorequlsion (Kamo, Takahashi). It was found that another unicellular orgam, Clamydomonas contains rhodopsinlike pigment which reacted with antibody against frog rhodopsin (Shinozawa). Photochemical process of sensory rhodopsin was studied by laser flash photolysis and new intermediate sR_L was found in in addition to sR_K and sR_M (Kobayashi, Tsuda). Photocycle of phoborhodopsin was studied by low temperature spectroscopy and P520 was found to form below -50゜C. Conformation of retinal in these pigments was studied by chemical extraction (Tsujimoto) and resonance Raman spectroscopy (Koyama) and shown that photochemical event in these pigments are photoisomerization between all trans retinal and 13゜cis retinal. In order to sutdy interaction between retinal and protein in these pigments, spin labeled retinal (Kusumi) and fluorescence labeled retinal (Kouyama) were used. Phototransduction in phototaxitic unicellular species is not known. It was shown that sensory rhodopsin did not transport proton (Ohno). However, G-protein was found in these organs (Watanabe).
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