The structure of hemocyanin in the partially oxygenated state.
Project/Area Number |
61580228
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
生物物性学
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Research Institution | University of Tsukuba |
Principal Investigator |
MAKINO Nobuo Institute of Basic Medical Sciences, Univ. of Tsukuba, 基礎医学系, 講師 (90101310)
|
Project Period (FY) |
1986 – 1987
|
Project Status |
Completed (Fiscal Year 1987)
|
Budget Amount *help |
¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1987: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1986: ¥600,000 (Direct Cost: ¥600,000)
|
Keywords | hemocyanin / cooperativity / allosteric protein / 四次構造 / 酸素結合 |
Research Abstract |
Hemocynains (Hc) are copper proteins which occur in many arthropods and molluscs. They bind molecular oxygen cooperatively and function as oxygen carriers in the hemolymph of the animals. In this study, the protein structure of partially oxygenated hemocyanin was examined by the dye (neutral red) binding method and also by UV-difference and circular dichroism spectrometries in order to obtain information on the mechanism of the cooperativity in the respiratory proteins. In this study, Hc from a spiny lobster, Panulirus japonicus, was uesd. It was found that the fractional change in the dye binding was considerably ahead of the average oxygen saturation of hemocyanin. On the contrary, the change in the absorption spectrum (in the range of 280 to 295 nm) was propotional to the fractional oxygen saturation. The spetral change seems to be due to the aromatic (probably tryptophane) residues near the oxygen binding site of Hc. It is suggested that structural changes near the protein (or subunit) surface, such as detected by the dye binding method, occurs considerably ahead of the average oxygen binding, while structural changes in the inner part of the protein (including the oxgen binding sites) takes place propotionally to the oxygen binding.
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Report
(2 results)
Research Products
(9 results)