| Project/Area Number |
12680663
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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 |
Biophysics
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| Research Institution | Kansai Medical University |
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Principal Investigator |
KIHARA Hiroshi Kansai Medical University,Professor, 医学部, 教授 (20049076)
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| Co-Investigator(Kenkyū-buntansha) |
AMEMIYA Yoshiyuki University of Tokyo, Professor, 大学院・物質創生系, 教授 (70151131)
TAKEMOTO Kuniko Kansai Medical University, Lecturer, 医学部, 講師 (80281509)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2001: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2000: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Keywords | Protein folding / Compaction of protein / Formation rate of alpha-helix / Subzero temperature / Stopped-flow / x-ray solution scattering / フォールディング / ビータラクトグロブリン / アポミオグロビン / ユビキティン / アルフアービータ変換 / 円偏光二色性 |
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| Research Abstract |
Protein takes (a) definite pathway(s) when it folds into its native form. It is so-called folding problem. One of the most important subject in the folding process is when and how the three major conformational formation takes place ; i.e. secondary structure formation, compaction and formation of the folding core.
Protein folding starts at the time range of sub-micro-seconds. We reduced this rate to millisecond region, by decreasing temperature so as to slow down the folding process. With the use of stopped-flow technique combined with circular dichroism, fluorescence and X-ray scattering, we could monitor formation of alpha-helix, folding core formation and compaction. Results so far obtained are ; (1) formation rate of alpha-helix is too fast to be monitored even at -38C. (2) In case of bovine beta-lactogloblulin, we monitored a phase of alpha-helix increase at -28C. (3) In case of ubiquitin, the initial burs phase of alpha-helical formation was observed at -20C.
From the findings above, it would be suggested that formation of alpha-helix is commonly observed at the early stage of the folding even in the case of beta-rich proteins.
Results above are also very consistent with findings observed by temperature-jump method, and thus demonstrate the importance of our methodology ; cooling down the folding process.
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