1992 Fiscal Year Final Research Report Summary
Separation and Purification of Protein by Crystallization
| Project/Area Number |
03650778
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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 |
化学工学
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| Research Institution | Osaka City University |
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Principal Investigator |
OOSHIMA Hiroshi Osaka City University, Department of Engineering, Associate Professor, 工学部, 助教授 (20112526)
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| Project Period (FY) |
1991 – 1992
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| Keywords | Crystallization / Protein / Bioseparation / Precipitation / Purification / Thermolysin / Primary particles / Polycrystal |
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| Research Abstract |
The fundamental research on the crystallization of protein was carried out. The objective was to upgrade the crystallization to a high level of protein purification method.
First, the mechanism of the crystallization of protein was investigated, by using two kinds of enzyme protein, thermolysin and lysozyme. The following results were obtained. 1) The crystallization proceeds stepwise : the formation of the primary particles with 60 nm in diameter and then the formation of the large crystal composing of the primary particles. 2) The rate of the crystal growth depends on the initial supersaturation ratio. There is an optimal supersaturation ratio at which the growth rate becomes maximal and the number of the crystals becomes minimal. The presence of the optimal supersaturation ratio can be explained by the consecutive mechanism of the crystallization described above. 3) The primary particles don t contain the third protein as the impurity. This result suggests that at least at the early stage of the crystallization of protein the attractive interaction between the molecules acts preferentially in the same molecules.
Second, a novel method of the purification of protein by the crystallization was proposed. The method includes the following operations : 1) to separate the primary particles, instead of the large crystal finally obtained ; 2) to utilize the difference in the rate of crystal growth between the protein in interest and the impurities : 3) to utilize the difference in the size of the precipitates between the protein in interest and the impurities.
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Research Products
(2 results)
