筋肉の力は,アクチンにステレオ特異的に結合されたミオシンヘッドによって生成されます
S Y Bershitsky1, A K Tsaturyan, O N Bershitskaya
1National Institute for Medical Research, Mill Hill, London, UK.
Nature
|July 10, 1997
まとめ
筋肉力の生成には,アクチンに結合するミオシンクロスブリッジが含まれる. 私たちの研究は,クロスブリッジが非特異的結合からステレオ特異的結合への移行に伴い,力が増大することを示し,アクチンヘリックスにラベルを付けています.
科学分野:
- 筋肉の生理学と生物物理学
- 筋肉の収縮の分子メカニズム
背景:
- 筋肉の力は,アクチンと相互作用するミオシンクロスブリッジによって生成されます.
- ほとんどのミオシンクロスブリッジは,対比収縮時に結合するが,ステレオ特異的に結合する部分はわずかである.
研究 の 目的:
- 筋肉の緊張に寄与するクロスブリッジの割合を決定する.
- 力の発生中に接続されたクロスブリッジの構造変化を調査する.
主な方法:
- 浸透したカエルの筋肉繊維におけるX線 difraktion パターンの監視.
- 誘導する緊張は,活性化された筋肉繊維の温度上昇 (5-6°Cから16-19°C) を通じて上昇します.
主要な成果:
- 繊維の硬さや特定のX線反射の有意な変化なしに,緊張の1.7倍の増加が観察されました.
- (1,0) 赤道反射の強度が20%低下し,最初のアクチン層の線強度が13%増加した.
- これらの変化は,アクチンに対する非特異的結合からステレオ特異的結合へのクロスブリッジの移行を示しています.
結論:
- 筋肉力の生成は,非特異的結合からステレオ特異的結合へのクロスブリッジの移行と関連しています.
- ステレオ特異的に結合されたミオシンクロスブリッジは,力生成中にアクチンヘリックスに特異的にラベルを付けます.
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