troponin

[ troh-puh-nin, trop-uh- ]

noun

, Biochemistry.

1. a protein of muscle tissue that binds calcium ions and is involved in contraction.

troponin

/ trō′pə-nĭn,trŏp′ə- /

1. One of the proteins that make up the thin filaments of muscle tissue and that regulate muscle contraction and relaxation. Troponin occurs in three forms bound together in a complex. One of the three forms is a receptor of calcium ions that induces structural changes that allow the actin in the thin filaments to interact with myosin, causing contraction.

Word History and Origins

Origin of troponin¹

1965–70; tropo(myosin) ( tropo-, myosin ) + -n- (of uncertain origin) + -in ²