troponin

American

[troh-puh-nin, trop-uh-] / ˈtroʊ pə nɪn, ˈtrɒp ə- /

noun

Biochemistry.

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

troponin Scientific

/ trō′pə-nĭn,trŏp′ə- /

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.

Etymology

Origin of troponin

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

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Most affected individuals show elevated levels of cardiac troponin in their blood, a widely used marker of heart muscle injury.

From Science Daily • Dec. 27, 2025

"My troponin levels, which is a heart attack marker, were extremely high."

From BBC • Feb. 13, 2025

The thin filament consists of F-actin, troponin, tropomyosin, and nebulin.

From Science Daily • Nov. 1, 2023

The good news: In both studies, troponin levels quickly fell to normal.

From Science Magazine • Oct. 17, 2022

Two other components of the thin filament are tropomyosin and troponin.

From Textbooks • Jun. 9, 2022

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023