2006 Fiscal Year Final Research Report Summary
Molecular Mechanism for the Formation of Protein Aggregation Studied by High Pressure Infrared and Raman Spectroscopes
| Project/Area Number |
17550021
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Physical chemistry
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| Research Institution | Ritsumeikan University |
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Principal Investigator |
TANIGUCHI Yoshihiro Ritsumeikan University, College of Science and Engineering, Professor, 理工学部, 教授 (70066702)
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| Project Period (FY) |
2005 – 2006
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| Keywords | High Pressure / Infrared Spectroscopy / Raman Spectroscopy / Protein / Molecular Aggregates / Insulin / Albumin |
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| Research Abstract |
Pressure-and heat-induced aggregates of equine serum albumin (ESA) have been studied from the secondary stractural viewpoints using FT-IR spectroscopy. We showed the secondary structural differences between heat-and pressure0induced aggregates of ESA. The heat-induced irreversible aggregates of ESA are composed of the intermolecular β-sheet structure without binding thioflavin T and Congo red to be amorphous form. On the other hand, the pressure-induced reversible aggregates are composed of the random structure to be also amorphous form. From the comparison of pressure effects on ESA in native and reducing conditions of disulfide bridges, we demonstrate that the restriction of structure flexibility by disulfide bridges is an important factor for the reversibility of the pressure-induced aggregation
There were also two pressure effects on the secondary structure of insulin amyloid fibrils using FT-IR spectroscopy. One is the pressure effect on the secondary structural changes of insulin amyloid formed at different incubation time at 60℃ (early or mature amyloid fibrils) Another is the pressure effects on the formational rate of insulin amyloid fibrils. It was clarified that early incubated amyloid fibril was unstable against pressure but manure amyloid fibril quite stable against pressure, even under above 1 GPa. And the activation volume on the process of amyloid fibril formation was large positive values.
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