Molecular mechanism of force generation in muscle fibers

自笼养三磷酸腺苷和笼养钙被引入以来，脱膜肌纤维已成为阐明肌肉收缩分子机制的重要准备。Yamada研究了一种通过使用荧光核苷酸类似物标记的肌肉纤维的新型荧光信号。Sugi研究了化学-机械能量转换的效率，并展示了如何根据肌肉应该工作的负荷来确定效率。Hiratsuka开发了一种新的荧光ATP类似物，用于研究化学-机械能量转换。Arata旋转标记了肌肉纤维中肌球蛋白头部的底部，并表明即使在收缩过程中，它们也是随机定向的。Hotta产生了几个有用的果蝇飞行肌肉突变，其中肌动蛋白分子发生了突变。T.Wakabayashi使用冷冻电子显微镜，片山使用电子显微镜快速冷冻深蚀刻复制品图像来直接观察产生力的十字桥。石田利用光钳研究了单马达分子的滑动机理。K.Wakabayashi、Yagi和Umazume研究了收缩肌肉纤维的时间分辨X射线衍射。柳田能够直接观察到单个肌球蛋白分子结合和切割ATP分子并产生作用力。Iino和Kurebayashi研究了兰尼定受体的亚型与兴奋-收缩偶联的关系。Ohtsuki研究了肌钙蛋白T在收缩系统钙调节机制中所起的作用。Tawada和KoDama对这个问题进行了理论和热力学方面的研究。

Since the introduction of caged ATP and caged calcium demembranated skinned muscle fibers have become more important preparation for elucidating the molecular mechanism of muscle contraction. Yamada studied a novel fluorescence signal from muscle fibers labeled by using a fluorescent nucleotide analog. Sugi studied the efficiency of chemo-mechanical energy conversion and showed how the efficiency was determined due to the load against which muscle should work. Hiratsuka developed a new fluorescent ATP analogue useful for studying the chemo-mechanical energy conversion. Arata spin-labeled the base part of the myosin head in muscle fibers and showed that they were randomly oriented even during contraction. Hotta produced several useful mutants of Drosophila flight muscles in which actin molecules were mutated. T.Wakabayashi used cryo electron microscopy and Katayama used quick-freeze deep-etch replica images by electron microscopy to directly observe force-generating crossbridges. Ishiwata studied the mechanism of sliding of single motor molecules by using optical tweezers. K.Wakabayashi, Yagi and Umazume studied time-resolved X-ray diffraction of contracting muscle fibers. Yanagida was able to directly observe single myosin molecules to bind and cleave ATP molecules and to produce force. Iino and Kurebayashi studied subtypes of ryanodine receptors in relation to the excitation-contraction coupling. Ohtsuki studied the role playd by troponin T associated with the mechanism of calcium regulation of the contractile system. Tawada and Kodama worked on theoretical as well as thermodynamical approach to the problem.