troponin tro·po·nin (trō'pə-nĭn, trŏp'ə-)
A calcium-regulated protein in muscle tissue occurring in three subunits with tropomyosin.
|troponin (trō'pə-nĭn, trŏp'ə-) Pronunciation Key
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.