2001 Fiscal Year Final Research Report Summary
Analysis on the early events of protein folding at subzero temperatures
| Project/Area Number |
12680663
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Biophysics
|
|---|
| Research Institution | Kansai Medical University |
|---|
Principal Investigator |
KIHARA Hiroshi Kansai Medical University,Professor, 医学部, 教授 (20049076)
|
|---|
| 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)
|
|---|
| Project Period (FY) |
2000 – 2001
|
| Keywords | Protein folding / Compaction of protein / Formation rate of alpha-helix / Subzero temperature / Stopped-flow / x-ray solution scattering |
|---|
| 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.
|
