Grant-in-Aid for Scientific Research (B)
|Allocation Type||Single-year Grants |
Applied materials science/Crystal engineering
|Research Institution||TOHOKU UNIVERSITY |
SAZAKI Gen Inst. Materials Research, Tohoku Univ., Research Assoc., 金属材料研究所, 助手 (60261509)
MATSUURA Yoshiki Inst. Protein Research, Osaka Univ., Assoc. Prof., 蛋白質研究所, 助教授 (90029968)
MIYASHITA Satoru Inst. Materials Res., Tohoku Univ., Research Assoc., 金属材料研究所, 助手 (00219776)
DURBIN Stephen Duan Inst. Materials Res., Tohoku Univ., Assoc. Prof., 金属材料研究所, 助教授 (10301045)
HASEGAWA Kazuhiro Inst. Fermentation Res., Ajinomoto Co., Researcher, 発酵技術研究所, 研究員
|Project Period (FY)
1998 – 1999
Completed (Fiscal Year 1999)
|Budget Amount *help
¥12,500,000 (Direct Cost: ¥12,500,000)
Fiscal Year 1999: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1998: ¥11,200,000 (Direct Cost: ¥11,200,000)
|Keywords||protein / crystal / magnetic field / orientation / lysozyme / crystal growth / convection / crystal perfection / protein / crystal / magnetic field / orientation / lysozyme / crystal growth / convection / crystal perfection / oriontation|
We chose hen egg-white lysozyme as a model protein, and studied a magnetic field effects on the crystallization of lysozyme crystals. Main results obtained are summarized as follows.
1. Magnetic orientation of the crystals
Magnetic orientation of protein crystals could be controlled by changing the growth rate and depth of the crystallization container in addition to the magnetic field strength.
2. Growth rate of the crystals
In situ observation of growing protein crystals under 11T revealed that a magnetic field decreased the growth rate of the crystals.
3. Damping of convection in NaCl aqueous solution
In situ observation of temperature-driven convection in NaCl aqueous solution showed that a magnetic field damped the convection even in the case of "aqueous solution".
4. Improvement of the quality of the crystal
Rocking curve measurement of orthorhombic lysozyme crystals grown under 10T revealed that a magnetic field drastically increased the "crystal perfection" of protein single crystal., and gave higher diffraction limit and smaller X-ray radiation damage.
5. Effects of other external force I : high pressure
With an increase in hydrostatic pressure, solubility of tetragonal lysozyme crystals increased, though that of orthorhombic one decreased. Increase in surface energy decreased the growth rate of tetragonal and orthorhombic crystals.
6. Effects of other external force II : microgravity
Microgravity experiments using dropping facility revealed that 1) Grashoff number could be a good measure to predict buoyancy convection, and that 2) Marangoni convection at water-air interface decreased to less than 10% within 10-15 min because of the contamination of the interface.