Topographical studies on subunit polypeptides of oxygen-evolving PS II preparations by reversible crosslinking.
| Project/Area Number |
60540440
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
植物生理学
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| Research Institution | Science University of Tokyo |
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Principal Investigator |
ENAMI Isao Faculty of Science, Science University of Tokyo. Lecturer, 理学部, 講師 (40084305)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1986: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1985: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Oxygen-evolving system / Photosystem II / Chlorophyll-binding protein / Phycobilisome / Bifunctional reagent / Crosslinking / サブユニット間のトポロジー |
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| Research Abstract |
Oxygen-evolving membrane preparations contain several intrinsic polypeptides including two chlorophyll-carrying subunit polypeptides of about 47 and 43-40 kDa, three extrinsic proteins of 33, 24 and 18 kDa involving in water oxidation and antenna pigment complexes such as light-harvesting chlorophyll a/b proteins (LHCP) in higher plants and phycobiliproteins in cyanobacteria. In this study, we examined the nearest neighbor relationships among subunit polypeptides of two oxygen-evolving preparations by reversible crosslinking.
1. The nearest neighbor relationships among subunit polypeptides of spinach oxygen-evolving membrane were studied with a cleavable bifunctional crosslinking reagent, dithiobis(succinimidyl propionate) with a maximum molecular span of 12 <ang> . Of the three extrinsic proteins which are associated with water oxidation, the 33 kDa protein was found to crosslink with the 47 kDa subunit polypeptide of the photosystem II reaction center complex, whereas the 18 and 24 kDa proteins crosslinked with each other. The association of the 33 kDa protein with the 47 kDa protein suggests that the latter protein plays an important role in water oxidation.
2. The nearest neighbor relationships among polypeptides of synechococcus oxygen-evolving particles which retains a small amount of allophycocyanin were also examined. Crosslinking and subsequent cleaving of disulfide bonds of the crosslinked product showed that an allophycocyanin species which emits a long wavelength fluorescence band at 77K is crosslinked with the particles. Two-dimensional SDS polyacrylamide gel electrophoresis revealed that the phycobiliprotein is specifically crosslinked with a chlorophyll-carrying 40 kDa protein of the photosystem II reaction center complex. The results suggest that the 40 kDa apoprotein plays a key role in the excitation energy transfer from phycobilisomes to the photosystem II reaction center.
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Report
(1 results)
Research Products
(6 results)
