A myosin II nanomachine mimicking the striated muscle

• Published in: Nature communications Vol. 9; no. 1; pp. 3532 - 10
• Main Authors: Pertici, Irene, Bongini, Lorenzo, Melli, Luca, Bianchi, Giulio, Salvi, Luca, Falorsi, Giulia, Squarci, Caterina, Bozó, Tamás, Cojoc, Dan, Kellermayer, Miklós S Z, Lombardi, Vincenzo, Bianco, Pasquale
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 30.08.2018; Nature Publishing Group UK; Nature Portfolio
• Subjects: Actin; Actin Cytoskeleton - metabolism; Actin Cytoskeleton - physiology; Adenosine Triphosphate - metabolism; Animals; ATP; Cardiac muscle; Contraction; Cytoskeleton; Dimers; Experiments; Kinetics; Lasers; Male; Mechanics; Mimicry; Molecular motors; Muscle contraction; Muscle Contraction - physiology; Muscle, Skeletal - metabolism; Muscle, Skeletal - physiology; Muscle, Striated - metabolism; Muscle, Striated - physiology; Muscles; Myosin; Myosin Type II - metabolism; Pharmacology; Proteins; Rabbits; Skeletal muscle; Velocity
• ISSN: 2041-1723; 2041-1723
• 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.