Answer:
tropomyosin
Explanation:
Tropomyosin is an elongated (α-helical coiled-coil) molecule that controls muscle contraction by blocking the binding of myosin to actin, thereby preventing cross-bridge formation required for muscle contraction. Tropomyosin is removed during muscle contraction, which is initiated by the release of calcium ions (Ca 2+) from the sarcoplasmic reticulum. Moreover, the complex troponin (composed of troponin C, troponin I, and troponin T proteins) binds to tropomyosin and helps to localize it on the actin filament.
