1994 Fiscal Year Final Research Report Summary
A kinetic study of salt-induced denaturation of actin during storage at low temperature
| Project/Area Number |
05660307
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Zootechnical science/Grassland science
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| Research Institution | Niigata University |
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Principal Investigator |
IKEUCHI Yoshihide Niigata University Applied Biological Chemistry Associate Professor, 農学部, 助教授 (90168112)
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| Co-Investigator(Kenkyū-buntansha) |
SUZUKI Atsushi Niigata University Applied Biological Chemistry Professor, 農学部, 教授 (40018792)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Actin / Tropomyosin / HMM / Denaturation / Curing / DNAase I |
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| Research Abstract |
The small amount of F-actomyosin complex acts as a cross-linker with the free myosin molecule on heating, and it is considered to be a prerequisite for actin-induced improvement in the gel formability of myosin. Therefore, the property of heat-induced gel of myosin depends on the stability of actin during treatment with salt. The present work was conducted to elucidate the mechanism of salt-induced denaturation of actin during incubation at a low temperature.
1. A kinetic analysis by measuring DNase l inhibition capacity of actin demonstrated that the denaturation of actin obeys the theory of an irreversible continuous reaction (F-ADP-actin ---> G-ADP-actin ---> denatured actin) when actin solution is incubated at a low temperature (0ﾟC).
2. The addition of a sufficient amount of ATP to an F-actin solution effectively retards the progress of the denaturation of actin. ATP is thought to stabilize the structure of G-actin depolymerized during treatment with salt. That is, the present of ATP retards the process of G-ADP-actin -->denatured actin.
3. It has become apparent that a small amount of HMM accelerates the rate of depolymerization of F-actin during incubation at 0ﾟC.As a result, released G-actin is presumed to enter quickly the denaturation process without ATP.
4. When tropomyosin was added to solution containing actin alone or actin-HMM complex, the denaturation of actin was suppressed remarkably between 0.2 M KCI and 0.6 M KCI.From this result, it is clear that tropomyosin stabilizes the actin filament against disassembly at ionic strengths lower than 0.6 M.KCI
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