noun, plural: troponins
A regulatory protein that is a complex of three polypeptides (i.e. troponin c, troponin i, and troponin t). It has an affinity for calcium ions and is associated with tropomyosin. Together with tropomyosin, it regulates actin–myosin interactions in skeletal and cardiac muscle contraction.
Troponin is made up of three regulatory proteins:
- Troponin c – binds with calcium ions
- Troponin i– binds with actin in thin filament
- Troponin t – binds with tropomysin
Word origin: From tropomyosin. Coined by the Japanese researchers Setsuro Ebashi and Ayako Kodama in 1966.
See also: tropomyosin