troponin

(noun)

a complex of three regulatory proteins that is integral to muscle contraction in skeletal and cardiac muscle, or any member of this complex

Related Terms

Examples of troponin in the following topics:

  • Regulatory Proteins

    • Tropomyosin and troponin prevent myosin from binding to actin while the muscle is in a resting state.
    • The protein complex troponin binds to tropomyosin, helping to position it on the actin molecule.
    • If present, calcium ions bind to troponin, causing conformational changes in troponin that allow tropomyosin to move away from the myosin-binding sites on actin.
    • Calcium then binds to troponin, causing the troponin to change shape and remove the tropomyosin from the binding sites.
    • Describe how calcium, tropomyosin, and the troponin complex regulate the binding of actin by myosin

  • ATP and Muscle Contraction

    • The muscle contraction cycle is triggered by calcium ions binding to the protein complex troponin, exposing the active-binding sites on the actin.

  • Excitation–Contraction Coupling

    • The action potential triggers the sarcoplasmic reticulum to release of Ca2+, which activate troponin and stimulate muscle contraction.

  • Skeletal Muscle Fibers

    • Thin filaments are composed of actin, tropomyosin, and troponin.