A myosin II nanomachine mimicking the striated muscle

作者：Pertici Irene; Bongini Lorenzo; Melli Luca; Bianchi Giulio; Salvi Luca; Falorsi Giulia; Squarci Caterina; Bozo Tamas; Cojoc Dan; Kellermayer Miklos S Z; Lombardi Vincenzo^*; Bianco Pasquale

来源：Nature Communications, 2018, 9(1): 3532.

DOI：10.1038/s41467-018-06073-9

The contraction of striated muscle (skeletal and cardiac muscle) is generated by ATP-dependent interactions between the molecular motor myosin II and the actin filament. The myosin motors are mechanically coupled along the thick filament in a geometry not achievable by single-molecule experiments. Here we show that a synthetic one-dimensional nanomachine, comprising fewer than ten myosin II dimers purified from rabbit psoas, performs isometric and isotonic contractions at 2 mM ATP, delivering a maximum power of 5 aW. The results are explained with a kinetic model fitted to the performance of mammalian skeletal muscle, showing that the condition for the motor coordination that maximises the efficiency in striated muscle is a minimum of 32 myosin heads sharing a common mechanical ground. The nanomachine offers a powerful tool for investigating muscle contractile-protein physiology, pathology and pharmacology without the potentially disturbing effects of the cytoskeletal-and regulatory-protein environment.

• 出版日期2018-8-30