Contractile proteins of muscle are actin and myosin, the main components of the thin and thick filaments, respectively. ... Troponin has three subunits: TnT, which binds to tropomyosin; TnC, which binds calcium; and TnI, which inhibits the actin–myosin interaction

The two contractile protein is present in skeletol muscle is actin and myosin. Actin is thin filament which is also called isotropic and myosin is thick filament which is also called anisotropic. Actin protein has globular protein and over it is a antiparallel sequence goes into this protein is called tropomyosin. Myosin protein has tail region and head region. Tail region of myosin is called heavymeromyosin and head region of myosin is called heavymeromyosin. In the head region of myosin a specific type of binding site is present is called active site. And another site is present is called Atp site where by the process of phosphorylation the atp gave own phosphate due to this whole process of mechanisms of contraction and relaxation.