Myosin, Myosin Thread
Myosin is the protein of the myofibril, the thick filament of the myofibril.
The myosin threads together with the actin filaments are the smallest units in the structure of the muscle cell. The myosin in it is also called the "motor protein" of the human body.
The muscle cell is shortened by a reaction induced by calcium and maintained by high-energy ATP, in which the filaments slide into each other.