2003 Fiscal Year Final Research Report Summary
Adsorption behavior of protein, porphyrins and lipid onto the oil/water interface -Estimation with the laser evanescent wave at the interface.
| Project/Area Number |
14340221
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
機能・物性・材料
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| Research Institution | Oita University |
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Principal Investigator |
ISHIKAWA Yuichi Oita University, Dept. of Applied Chemistry, Associate Professor, 工学部, 助教授 (30184500)
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| Project Period (FY) |
2002 – 2003
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| Keywords | evanescent wave / oil / water interface / estimation of molecular distribution / laser / protein adsorption / porphyrin adsorption / isoelectric point and adsorption / BSA protein |
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| Research Abstract |
Protein distribution around the oil-water interface was evaluated with evanescent wave emerged from the laser irradiation at the interface. The evanescent wave dipping into the aqueous phase allowed the molecule addressed at the region to ionize itself. The ionized molecules can be recognized as the change in electric current as long as some electric field is applied among the interface. Herein we tested to see if this method is applicable to adsorbed aqueous BSA proteins at the octane/water interface.
Dependence of laser irradiation angle to the interface allows us to estimate the concentration of the ionized molecule 160 nm in depth from the interface. In the case of positive electric field (+500 V) from the octane oil phase, anionic BSAs being above the isoelectric point (4.7) located near the interface by 30-40 nm in depth. On the contrary, cationic BSAs being below the isoelectric point were away from the interface by 80-90 nm form the interface. In addition to the influence of the charges of the protein and of the applied electric field, the manner of the adsorption such as an allosteric and Langmuir adsorptions were observed. Several chiral N-confused porphyrin derivatives were prepared in this research.
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