Development of novel therapeutic options for treating heart failure targeting the myosin light chain

开发针对肌球蛋白轻链的治疗心力衰竭的新治疗方案

• 批准号: 13670689
• 负责人: YAMASHITA Hiroshi
• 金额: $ 2.43万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13670689/
• 关键词: cardiac myosin; myosin light chain; in vitro motility assay; 筋収縮; 分子生物学; ミオシン; カルシウムイオン; アデノウイルス; カーボンファイバー; 心筋

A myosin molecule consists of two heavy chains and two pairs of light chains and converts chemical energy of ATP hydrolysis into mechanical work of muscle contraction. The light chains are located close to the heavy chain head domain which contains ATP- and actin-binding sites essential for the motor function. To study functional roles of the myosin light chains, we purified two cardiac myosins with identical heavy chain and different light chains and compared the motor function of these myosins using in vitro motility assay techniques, where mechanical interaction of actin and myosin was reconstituted in vitro. Although catalytic activity showed no difference, motor function of these myosin molecules showed remarkable difference : the myosin molecules with ventricular-type light chains generated higher average force compared to those with atrial-type light chains and had longer duration of force-generating interaction with actin, suggesting that the myosin light chains may play an important role in converting the chemical energy into mechanical work. The unique nature of the myosin light chain modifying force-generating ability of the molecule without changing ATP hydrolysis rate may provide a clue to novel treatment for heart failure augmenting contractile function without increasing ATP consumption and protecting cardiac muscles from deterioration in energy metabolism.

肌球蛋白分子由两条重链和两对轻链组成，将ATP水解的化学能转化为肌肉收缩的机械功。轻链位于重链头部结构域附近，该结构域包含对运动功能至关重要的ATP和肌动蛋白结合位点。为了研究肌球蛋白轻链的功能，我们纯化了两种相同重链和不同轻链的心肌肌球蛋白，并利用体外运动测试技术比较了这些肌球蛋白的运动功能，其中肌动蛋白和肌球蛋白的机械相互作用在体外进行了重组。虽然这些肌球蛋白分子的催化活性没有差异，但其运动功能却有显著差异：具有室型轻链的肌球蛋白分子比具有心房型轻链的肌球蛋白分子产生的平均作用力更大，并且与肌动蛋白的作用力持续时间更长，这表明肌球蛋白轻链可能在将化学能转化为机械功的过程中发挥重要作用。肌球蛋白轻链在不改变ATP水解率的情况下改变分子的力量产生能力的独特性质，可能为心力衰竭的新治疗提供线索，在不增加ATP消耗的情况下增强收缩功能，并保护心肌免受能量代谢的恶化。

项目成果

Saeki Y, Takigiku K, Iwamoto H, Yasuda S, Yamashita H, Sugiura S, Sugi H: "Protein Kinase A increases the rate of relaxation but not the rate of tension development in skinned rat cardiac muscle"Jpn J Physiol. 21. 427-433 (2001)

Saeki Y、Takigiku K、Iwamoto H、Yasuda S、Yamashita H、Sugiura S、Sugi H：“蛋白激酶 A 会增加剥皮大鼠心肌的松弛率，但不会增加张力发展率”Jpn J Physiol。

Yasuda S, Sugiura S, Kobayakawa N, Fujita H, Yamashita H, Katoh K, Saeki Y, Kaneko H, Suda Y, Nagai R, and Sugi H: "A novel method to study contraction characteristics of a single cardiac myocyte using carbon fibers coupled with a feedback system"Am J Phy

Yasuda S、Sugiura S、Kobayakawa N、Fujita H、Yamashita H、Katoh K、Saeki Y、Kaneko H、Suda Y、Nagai R 和 Sugi H：“一种使用碳纤维研究单个心肌细胞收缩特性的新方法

山下 尋史: "ミオシンモーターの力学特性"呼吸と循環. 50巻1号. 59-73 (2002)

Hirofumi Yamashita：“肌球蛋白运动的机械特性”呼吸与循环，第 50 卷，第 1. 59-73 期（2002 年）。

Yamashita H: "Motor function of myosin molecule"Kokyu to Junkan. 50. 59-73 (2002)

Yamashita H：“肌球蛋白分子的运动功能”Kokyu to Junkan。

Saeki Y, Takigiku K, Iwamoto H, Yasuda S, Yamashita H, Sugiura S and Sugi H: "Protein kinase A increases the rate of relaxation but not the rate of tension development in skinned rat cardiac muscle"Jpn J Physiol. 51. 427-433 (2001)

Saeki Y、Takigiku K、Iwamoto H、Yasuda S、Yamashita H、Sugiura S 和 Sugi H：“蛋白激酶 A 会增加剥皮大鼠心肌的松弛速率，但不会增加张力发展速率”Jpn J Physiol。