| Project/Area Number |
16540373
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Biophysics/Chemical physics
|
|---|
| Research Institution | Kansai Medical University |
|---|
Principal Investigator |
KIHARA Hiroshi Kansai Medical University, Faculty of Medicine, Professor, 医学部, 教授 (20049076)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MORITA Masayuki Kansai Medical University, Faculty of Medicine, Assistant Professor, 医学部, 講師 (20148555)
|
|---|
| Project Period (FY) |
2004 – 2006
|
| Project Status |
Completed (Fiscal Year 2006)
|
| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2006: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2005: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2004: ¥1,900,000 (Direct Cost: ¥1,900,000)
|
|---|
| Keywords | protein folding / alpha-helical burst / SH3 domain / beta-structure-rich protein / β構造蛋白質 / 蛋白質のフォールディング / 2次構造 / src SH3 / fyn SH3 / クライオストップトフロー / 円偏光二色性 / X線溶液散乱 / フォールディング / β構造 / SH3ドメイン蛋白質 / フォールディング中間体 |
|---|
| Research Abstract |
Protein folds via definite pathway. The purpose of the folding study is to find its folding pathway. We have developed cryo-stopped-flow apparatus with circular dichrosism, x-ray scattering and fluoresecence as probes. We have investigated various types of proteins. Results with alpha-helical protein show the folding rate of alpha-helix formation is so rapid that we cannot measure the rate of alpha-helix formation. In contrast, proteins, mainly consisting of beta-structure, take alpha-helix-rich intrmeditate at its earliest stage. We have focused the folding of SH3, which takes beta-conformation at its native state.
SH3 takes alpha-helix-rich intermediate at its earliest stage of folding. We then investigated other beta-structure-rich proteins, and found the intermediate appeared without exception. We compared the amplitude of the burst with other parameters, and found the burst amplitude has good relationship with the helical fraction calculated by a program, Helix2. The program is mainly based on helix-coil transition theory with experimental data of adjacent residues. This suggest that the initial folding cores are formed by the interaction of short-lived alpha-helices.
By the one residue mutation of SH3 (Alanine 45 to Glycine), we found the conformation changed from beta-rich to alpha-rich at pH3. This indicates the conversion of beta to alpha occurs more frequently than expected.
|
