Electron Microscopic Recording of the Power and Recovery Strokes of Individual Myosin Heads Coupled with ATP Hydrolysis: Facts and Implications
The most straightforward way to get information on the performance of individual myosin heads producing muscle contraction may be to record their movement, coupled with ATP hydrolysis, electron-microscopically using the gas environmental chamber (EC). The EC enables us to visualize and record ATP-in...
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MDPI AG
2018-05-01
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| Series: | International Journal of Molecular Sciences |
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| Online Access: | http://www.mdpi.com/1422-0067/19/5/1368 |
| _version_ | 1811301626280935424 |
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| author | Haruo Sugi Shigeru Chaen Tsuyoshi Akimoto |
| author_facet | Haruo Sugi Shigeru Chaen Tsuyoshi Akimoto |
| author_sort | Haruo Sugi |
| collection | DOAJ |
| description | The most straightforward way to get information on the performance of individual myosin heads producing muscle contraction may be to record their movement, coupled with ATP hydrolysis, electron-microscopically using the gas environmental chamber (EC). The EC enables us to visualize and record ATP-induced myosin head movement in hydrated skeletal muscle myosin filaments. When actin filaments are absent, myosin heads fluctuate around a definite neutral position, so that their time-averaged mean position remains unchanged. On application of ATP, myosin heads are found to move away from, but not towards, the bare region, indicating that myosin heads perform a recovery stroke (average amplitude, 6 nm). After exhaustion of ATP, myosin heads return to their neutral position. In the actin–myosin filament mixture, myosin heads form rigor actin myosin linkages, and on application of ATP, they perform a power stroke by stretching adjacent elastic structures because of a limited amount of applied ATP ≤ 10 µM. The average amplitude of the power stroke is 3.3 nm and 2.5 nm at the distal and the proximal regions of the myosin head catalytic domain (CAD), respectively. The power stroke amplitude increases appreciably at low ionic strength, which is known to enhance Ca2+-activated force in muscle. In both the power and recovery strokes, myosin heads return to their neutral position after exhaustion of ATP. |
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| id | doaj.art-3c54dfcdadf147eaaa2a27f8ae619308 |
| institution | Directory Open Access Journal |
| issn | 1422-0067 |
| language | English |
| last_indexed | 2024-04-13T07:12:16Z |
| publishDate | 2018-05-01 |
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| series | International Journal of Molecular Sciences |
| spelling | doaj.art-3c54dfcdadf147eaaa2a27f8ae6193082022-12-22T02:56:50ZengMDPI AGInternational Journal of Molecular Sciences1422-00672018-05-01195136810.3390/ijms19051368ijms19051368Electron Microscopic Recording of the Power and Recovery Strokes of Individual Myosin Heads Coupled with ATP Hydrolysis: Facts and ImplicationsHaruo Sugi0Shigeru Chaen1Tsuyoshi Akimoto2Department of Physiology, School of Medicine, Teikyo University, Tokyo, JapanDepartment of Integrated Sciences in Physics and Biology, College of Humanities and Science, Nihon University, Tokyo, JapanDepartment of Physiology, School of Medicine, Teikyo University, Tokyo, JapanThe most straightforward way to get information on the performance of individual myosin heads producing muscle contraction may be to record their movement, coupled with ATP hydrolysis, electron-microscopically using the gas environmental chamber (EC). The EC enables us to visualize and record ATP-induced myosin head movement in hydrated skeletal muscle myosin filaments. When actin filaments are absent, myosin heads fluctuate around a definite neutral position, so that their time-averaged mean position remains unchanged. On application of ATP, myosin heads are found to move away from, but not towards, the bare region, indicating that myosin heads perform a recovery stroke (average amplitude, 6 nm). After exhaustion of ATP, myosin heads return to their neutral position. In the actin–myosin filament mixture, myosin heads form rigor actin myosin linkages, and on application of ATP, they perform a power stroke by stretching adjacent elastic structures because of a limited amount of applied ATP ≤ 10 µM. The average amplitude of the power stroke is 3.3 nm and 2.5 nm at the distal and the proximal regions of the myosin head catalytic domain (CAD), respectively. The power stroke amplitude increases appreciably at low ionic strength, which is known to enhance Ca2+-activated force in muscle. In both the power and recovery strokes, myosin heads return to their neutral position after exhaustion of ATP.http://www.mdpi.com/1422-0067/19/5/1368myosin head power strokemyosin head recovery strokemuscle contractiongas environmental chambermyosin head neutral configuration |
| spellingShingle | Haruo Sugi Shigeru Chaen Tsuyoshi Akimoto Electron Microscopic Recording of the Power and Recovery Strokes of Individual Myosin Heads Coupled with ATP Hydrolysis: Facts and Implications International Journal of Molecular Sciences myosin head power stroke myosin head recovery stroke muscle contraction gas environmental chamber myosin head neutral configuration |
| title | Electron Microscopic Recording of the Power and Recovery Strokes of Individual Myosin Heads Coupled with ATP Hydrolysis: Facts and Implications |
| title_full | Electron Microscopic Recording of the Power and Recovery Strokes of Individual Myosin Heads Coupled with ATP Hydrolysis: Facts and Implications |
| title_fullStr | Electron Microscopic Recording of the Power and Recovery Strokes of Individual Myosin Heads Coupled with ATP Hydrolysis: Facts and Implications |
| title_full_unstemmed | Electron Microscopic Recording of the Power and Recovery Strokes of Individual Myosin Heads Coupled with ATP Hydrolysis: Facts and Implications |
| title_short | Electron Microscopic Recording of the Power and Recovery Strokes of Individual Myosin Heads Coupled with ATP Hydrolysis: Facts and Implications |
| title_sort | electron microscopic recording of the power and recovery strokes of individual myosin heads coupled with atp hydrolysis facts and implications |
| topic | myosin head power stroke myosin head recovery stroke muscle contraction gas environmental chamber myosin head neutral configuration |
| url | http://www.mdpi.com/1422-0067/19/5/1368 |
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