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Changes in rabbit skeletal myosin and its subfragments under high hydrostatic pressure
Tomohito Iwasaki1, Katsuhiro Yamamoto
1Department of Food Science, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan. iwasaki@rakuno.ac.jp
International Journal of Biological Macromolecules
|November 11, 2003
Summary
High hydrostatic pressure causes denaturation in rabbit skeletal myosin, primarily affecting the myosin head. This pressure-induced denaturation shows hysteresis, indicating a stable, partially denatured state at high pressures.
Area of Science:
- Biochemistry
- Biophysics
Background:
- Myosin is a crucial motor protein in muscle contraction.
- Understanding protein stability under pressure is vital for various biological and industrial applications.
Purpose of the Study:
- To investigate the pressure-induced denaturation of rabbit skeletal myosin and its subfragments.
- To identify the most pressure-sensitive region of the myosin molecule.
Main Methods:
- Intrinsic fluorescence spectroscopy to monitor spectral shifts.
- 8-Anilinonaphthalene-1-sulfonic acid (ANS) fluorescence to assess conformational changes.
- Application of hydrostatic pressure up to 400 MPa.
Main Results:
- A 4 nm red shift in intrinsic fluorescence and increased ANS fluorescence indicated myosin denaturation under pressure.
- The center of spectral mass of myosin and subfragments decreased linearly with increasing pressure.
- The myosin head (S1) exhibited hysteresis and stability in a partially denatured state above 350 MPa.
Conclusions:
- The myosin head is the most pressure-sensitive domain of myosin.
- Pressure-induced denaturation of myosin is accelerated during pressurization.
- Myosin S1 can exist in a stable, partially denatured state under high hydrostatic pressure.