Nature's strategy for optimizing power generation in insect flight muscle.
Nature's strategy for optimizing power generation in insect flight muscle.
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DOI：
10.1007/0-387-24990-7_12
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发表时间：
2005
影响因子：
--
通讯作者：
D. Maughan;J. Vigoreaux
中科院分区：
文献类型：
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作者：
D. Maughan;J. Vigoreaux
横纹肌中肌动球蛋白马达最重要的机械功能是产生动力，特别是在以振荡方式操作的系统中。由于所有横纹肌都有相同的基本运动蛋白（肌球蛋白II），出现了这样的问题，即肌节的什么结构修饰已经进化到允许运动蛋白产生的振荡功和功率不仅被放大，在本章中，我们讨论了肌丝晶格的关键结构特征，这些特征已经进化到增强肌肉系统的功能。振荡功和功率输出，果蝇间接飞行肌（IFM）为例。昆虫飞行肌肉特别具有增强动力的特征，因为昆虫飞行比其他形式的动物运动需要更高的每克体重功率输出（马尔登，2000; Tregear，1983）。这些特征包括：1）加强肌节的薄弱环节，2）定向肌球蛋白分子的头部以获得最佳发电，以及3）改变肌球蛋白头部的动力学。我们重点关注肌球蛋白II的替代形式和与粗肌丝相关的蛋白质，这些蛋白质具有这些功能（图1），特别是那些已经产生突变的蛋白质，以及那些已经在体内和体外检查过其肌肉特性的蛋白质。
The most important mechanical fiinction of the actomyosin motor in striated muscles is to generate power, particularly in systems that operate in an oscillatory manner. Since all striated muscles have the same basic motor protein (myosin II), the question arises as to what structural modifications of the sarcomere have evolved to allow oscillatory work and power generated by the motor proteins to not only be amplified, but also to be so well tuned to the operating frequency of the muscle system.In this chapter we discuss key structural features of the myofilament lattice that have evolved to enhance oscillatory work and power output, using Drosophila indirect flight muscle (IFM) as an example. Insect flight muscle is particularly endowed with powerenhancing features since insect flight requires higher power output per gram body weight than other forms of animal locomotion (Marden, 2000; Tregear, 1983). These features include 1) strengthening the weak links of the sarcomere, 2) orienting the head of the myosin molecule for optimum power generation, and 3) modifying the kinetics of the myosin head. We focus on alternative forms of myosin II and proteins associated with the thick filament that serve these functions (Fig. 1), particularly those in which mutations have been generated and whose muscle properties have been examined in vivo and in vitro.