1996 Fiscal Year Final Research Report Summary
Development of novel X-ray diffraction measurement for biological macromolecular assemblies
| Project/Area Number |
06558102
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 試験 |
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| Research Field |
Biophysics
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| Research Institution | Osaka University (1995-1996)
The University of Tokushima (1994) |
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Principal Investigator |
TSUKIHARA Tomitake Osaka University, Institute for Protein Research, Professor, 蛋白質研究所, 教授 (00032277)
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| Project Period (FY) |
1994 – 1996
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| Keywords | Biological macromolecular assemblies / Crystal structure analysis / X-ray diffraction / Proteins |
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| Research Abstract |
Unit cell volumes of biological macromolecular assemblies are as large as more than ten times of those of protein crystals. There remain several problems to be solved in x-ray diffraction experiments for the biological macromolecular assemblies. In the case of crystals with large unit cell, distances between diffraction spots so short that it is difficult to measure intensity of each diffraction separately. Since intensity of each diffraction spot is proportional to reciprocal of unit cell volume of crystal, diffraction from crystals with large unit cells is too weak to measure their intensity accurately. Thus we have initiated this research to develop new methods to collect-x-ray diffraction data of the biological macromolecular assemblies.
Results obtained in the present research are summarized as follows : Small angle oscillation method about any direction splits each diffraction spot from the others and increases S/N of intensity data. Consequently, intensity data of crystals with unit cell dimensions of 500 is able to carried out by the method with 0.5 degree oscillation. The small angle oscillation method does not enable to decrease overlapping between diffraction spots, but also increase accuracy of intensity of each diffraction. The oscillation method about any direction reduces systematic error in observed intensity data.
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